Tag Archives: South China Sea

Taiwan scrambles jets, navy as China aircraft carrier enters Taiwan Strait

China carrier

TAIPEI (Reuters) – Taiwan scrambled jets and navy ships on Wednesday as a group of Chinese warships, led by its sole aircraft carrier, sailed through the Taiwan Strait, the latest sign of heightened tension between Beijing and the self-ruled island.

China’s Soviet-built Liaoning aircraft carrier, returning from exercises in the South China Sea, was not encroaching in Taiwan’s territorial waters but entered its air defense identification zone in the southwest, Taiwan’s defense ministry said.

As a result, Taiwan scrambled jets and navy ships to “surveil and control” the passage of the Chinese ships north through the body of water separating Taiwan and China, Taiwan defense ministry spokesman Chen Chung-chi said.

Taiwan military aircraft and ships have been deployed to follow the carrier group, which is sailing up the west side of the median line of the strait, he said.

Taiwan’s top policymaker for China affairs urged Beijing to resume dialogue, after official communication channels were suspended by Beijing from June.

“I want to emphasize our government has sufficient capability to protect our national security. It’s not necessary to overly panic,” said Chang Hsiao-yueh, minister for Taiwan’s Mainland Affairs Council, during a news briefing in response to reporters’ questions on the Liaoning.

“On the other hand, any threats would not benefit cross-Strait ties,” she said.

China has said the Liaoning was on an exercise to test weapons and equipment in the disputed South China Sea and its movements complied with international law.

On the weekend, a Chinese bomber flew around the Spratly Islands in a show of “strategic force”, a U.S. official said on Tuesday.

The latest Chinese exercises have unnerved Beijing’s neighbors, especially Taiwan which Beijing claims as its own, given long-running territorial disputes in the South China Sea.

Chinese Vice Foreign Minister Liu Zhenmin said China’s ships “couldn’t always remain in port” and the navy had to hone its capabilities.

“The Taiwan Strait is an international waterway shared between the mainland and Taiwan. So, it is normal for the Liaoning to go back and forth through the Taiwan Strait in the course of training, and it won’t have any impact on cross-Strait relations,” Liu said at a briefing on Asia-Pacific security.

China claims most of the energy-rich waters of the South China Sea, through which about $5 trillion in ship-borne trade passes every year. Neighbors Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims.

China distrusts Taiwan President Tsai Ing-wen and has stepped up pressure on her after U.S. President-elect Donald Trump broke years of diplomatic protocol and took a congratulatory call last month from her.

Trump then riled China by casting doubt on the “one China” policy that Beijing regards as the basis of U.S.-Chinese relations.

Tsai drew anger from China again when she met senior U.S. Republican lawmakers in Houston on Sunday en route to Central America, in a transit stop that Beijing had asked the United States to not allow.

Beijing suspects Tsai wants to push for the island’s formal independence, a red line for the mainland, which has never renounced the use of force to bring what it deems a renegade province under its control.

Tsai says she wants to maintain peace with China.

(Reporting by J.R. Wu and Faith Hung; Additional reporting by Michael Martina in Beijing; Editing by Michael Perry, Robert Birsel)

Chinese bomber flies round contested Spratlys in show of force: U.S. official

Chinese vessels in South China Sea

WASHINGTON (Reuters) – A Chinese H-6 strategic bomber flew around the Spratly Islands at the weekend in a new show of force in the contested South China Sea, a U.S. official said on Tuesday.

It was the second such flight by a Chinese bomber in the South China Sea this year. The first was on Jan. 1, said the official, who spoke on condition of anonymity.

The flight could be seen as a show of “strategic force” by the Chinese, the official said.

It comes after U.S. President-elect Donald Trump has signaled a tougher approach to China when he takes office on Jan. 20, with tweets criticizing Beijing for its trade practices and accusing it of failing to help rein in nuclear-armed North Korea.

Commander Gary Ross, a Pentagon spokesman, said he had no specific comment on China’s recent bomber activities, but added: “we continue to observe a range of ongoing Chinese military activity in the region‎.”

In December, China flew an H-6 bomber along the “nine-dash line” it uses to map its claim to nearly all of the South China Sea, a strategic global trade route. That flight also went around Taiwan, which China views as a renegade province.

In August, China conducted “combat patrols” near contested islands in the South China Sea.

Trump has enraged Beijing by breaking with decades of U.S. policy and speaking to the Taiwanese president by telephone.

A state-run Chinese newspaper warned Donald Trump on Sunday that China would “take revenge” if he reneged on the U.S. one-China policy, only hours after Taiwan’s president made a controversial stopover in Houston.

Last week China said that a group of Chinese warships led by its sole aircraft carrier was testing weapons and equipment in exercises this week in the South China Sea, where territory is claimed by several regional states.

U.S. warships conducted what they call “freedom of navigation” patrols through the South China Sea over the past year amid growing concern about Chinese construction of air strips and docks on disputed reefs and islands.

(Reporting by Idrees Ali and David Brunnstrom; Editing by James Dalgleish)

Philippines says South China Sea ruling not on agenda at ASEAN summit

Philippine President

MANILA (Reuters) – An arbitration court ruling that rejected China’s claims to the South China sea and strained Chinese relations with the Philippines will not be on the agenda of this year’s Southeast Asian summit, a senior Philippine official said on Thursday.

Philippine President Rodrigo Duterte reiterated last month he wanted to avoid confrontation with China and saw no need to press Beijing to abide by the July ruling that went in favor of the Philippines.

“The Hague ruling will not be on the agenda in the sense that it’s already part of international law,” Foreign Affairs Undersecretary Enrique Manalo told reporters ahead of the Association of Southeast Asian Nations (ASEAN) meeting chaired by the Philippines in April.

“So we really can’t discuss the ruling. It’s there.”

The July 2016 ruling rejected China’s territorial claims over much of the South China Sea. Beijing declared the decision as “null and void”, but called on countries involved in the dispute to start talks again to peacefully resolve the issue.

What the 10-member ASEAN will focus on is the completion of a framework for a code of conduct to ease tension in the disputed waters, Manalo said.

“We hope we will have a pleasant scenario during our chairmanship. We will talk to China in a way we will put forth our interest just as we expect china will put forth theirs,” Manalo said.

Since 2010, China and the ASEAN have been discussing a set of rules aimed at avoiding conflict. China claims most of the energy-rich waters through which about $5 trillion in ship-borne trade passes every year. Neighbors Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims.

At the ASEAN summit last year, China’s closest ASEAN ally, Cambodia, blocked any mention of the court ruling against Beijing in a joint statement.

Duterte made a stunning U-turn in foreign policy a few months ago when he made overtures toward China and started berating traditional ally the United States.

(Reporting by Karen Lema; Editing by Nick Macfie)

China says aircraft carrier testing weapons in South China Sea drills

Chinese aircraft carrier in South China Sea

BEIJING (Reuters) – A group of Chinese warships led by its sole aircraft carrier is testing weapons and equipment in exercises this week in the South China Sea that are going to plan, China’s foreign ministry said Wednesday.

Exercises by the ships, in particular the aircraft carrier Liaoning, since last month have unnerved China’s neighbors, especially at a time of heightened strain with self-ruled Taiwan, which Beijing claims as its own, and given long-running territorial disputes in the South China Sea.

China says the Soviet-built Liaoning and the other ships conduct routine exercises that comply with international law.

“The Liaoning aircraft carrier group in the South China Sea is carrying out scientific research and training, in accordance with plans,” Chinese foreign ministry spokesman Geng Shuang told a regular news briefing.

“The purpose is to test the performance of weapons and equipment,” he said.

The People’s Liberation Army Navy said on its official microblog this week that the aircraft carrier conducted drills in the South China Sea with its fighter jets and helicopters.

U.S. warships have also been conducting what they call “freedom of navigation” patrols through the South China Sea over the past year as concern grows about Chinese construction of air strips and docks on disputed reefs and islands.

The group of warships sailed through waters south of Japan and then rounded east and south of Taiwan late last month on their way to the south China province of Hainan.

Taiwan’s defence minister warned at the time that “the threat of our enemies is growing day by day”.

Taiwan media have reported that the Liaoning could sail north up the median line of the Taiwan Strait, the narrow body of water separating Taiwan and China, on its way to its home port of Qingdao.

Taiwan’s defence ministry said the talk about the timing and northward route of the Liaoning was speculation, and it would make preparations based on the situation and “maintain its grasp of the movements” of the ship.

Business relations between mainland China and Taiwan have grown significantly over the past decade but tension has increased since the island elected a president from an independence-leaning party last year.

China distrusts President Tsai Ing-wen and has stepped up pressure on her following a protocol-breaking phone call between her and U.S. President-elect Donald Trump last month.

Beijing suspects Tsai wants to push for the island’s formal independence, a red line for the mainland, which has never renounced the use of force to bring what it deems a renegade province under its control.

Tsai says she wants to maintain peace with China.

(Reporting by Michael Martina; Additional reporting by J.R. Wu in Taipei)

Taiwan warns of increasing threat as Chinese warships conduct drill

A general view shows navy soldiers standing on China's first aircraft carrier "Liaoning" as it is berthed in a port in Dalian, northeast China's Liaoning province,

By J.R. Wu

TAIPEI (Reuters) – Taiwan warned on Tuesday that “the threat of our enemies is growing day by day”, as Chinese warships led by the country’s sole aircraft carrier sailed towards the island province of Hainan through the South China Sea on a routine drill.

China has given few details of what the Soviet-built Liaoning aircraft carrier is up to, save that it is on a routine exercise. Taiwan has said the aircraft carrier skirted waters outside of its eastern air defense identification zone.

The carrier is expected to arrive at a Chinese military base on the southern Chinese island of Hainan late on Tuesday, Taiwan’s defense ministry said.

The drill comes amid renewed tension over Taiwan, which China claims as its own and says is ineligible for state-to-state relations, following U.S. President-elect Donald Trump’s telephone call with the island’s president that upset Beijing.

“The threat of our enemies is growing day by day. We should always be maintaining our combat alertness,” Taiwan Defence Minister Feng Shih-kuan said. “We need to strengthen the training (of our soldiers) so that they can not only survive in battle but also destroy the enemy and accomplish the mission.”

Feng’s remarks were given in a speech Tuesday at a ministry event marking the promotion of senior military officers.

China’s air force conducted long-range drills this month above the East and South China Seas that rattled Japan and Taiwan. China said those exercises were also routine.

China claims most of the South China Sea, through which about $5 trillion in ship-borne trade passes every year. Neighbours Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims.

The Pentagon did not directly comment on the latest drill but said that the United States recognizes lawful use of sea and airspace in accordance to international law.

“We continue to closely monitor developments in the region. We do not have specific comments on China’s recent naval activities, but we continue to observe a range of ongoing Chinese military activity in the region‎,” Pentagon spokesman Gary Ross told Reuters.

The Liaoning has taken part in previous exercises, including in the South China Sea, but China is years away from perfecting carrier operations similar to those the United States has practiced for decades.

Last December, the defense ministry confirmed China was building a second aircraft carrier but its launch date is unclear. The aircraft carrier program is a state secret.

Beijing could build multiple aircraft carriers over the next 15 years, the Pentagon said in a report last year.

China has claimed sovereignty over Taiwan since 1949, when Mao Zedong’s Communist forces won the Chinese civil war and Chiang Kai-shek’s Nationalists fled to the island.

Beijing has vowed to bring Taiwan under its rule, by force if necessary.

(Reporting by J.R. Wu; Additional reporting by Tim Kelly in Tokyo; Writing by Ben Blanchard; Editing by Nick Macfie)

China returns underwater drone, U.S. condemns “unlawful” seizure

The oceanographic survey ship, USNS Bowditch, is shown September 20, 2002, which deployed an underwater drone seized by a Chinese Navy warship in international waters in South China Sea,

By Ben Blanchard

BEIJING, Dec 20 (Reuters) – China has returned a U.S. underwater drone taken by one of its naval vessels in the
disputed South China Sea last week after what it said were friendly talks with the United States, which reiterated its criticism of the “unlawful” seizure.

The taking of the unmanned underwater vehicle in international waters near the Philippines triggered a diplomatic protest and speculation about whether it would strengthen U.S. President-elect Donald Trump’s hand as he seeks a tougher line with China.

A Chinese naval ship took the drone, which the Pentagon says uses unclassified, commercially available technology to collect oceanographic data, on Thursday about 50 nautical miles northwest of Subic Bay in the Philippines.

China’s defence ministry said in a brief statement the drone had been given back to the United States on Tuesday.

“After friendly consultations between the Chinese and U.S. sides, the handover work for the U.S. underwater drone was smoothly completed in relevant waters in the South China Sea at midday,” the ministry said.

The defence ministry declined to give more details about the handover when contacted by Reuters.

The Pentagon said the vehicle had been handed over to the guided missile destroyer USS Mustin near where it had been “unlawfully seized”. It called on China to comply with international law and refrain from further efforts to impede lawful U.S. activities.

“The U.S. remains committed to upholding the accepted principles and norms of international law and freedom of navigation and overflight and will continue to fly, sail, and operate in the South China Sea wherever international law allows,” Pentagon Press Secretary Peter Cook said in a statement.

Chinese foreign ministry spokeswoman Hua Chunying referred questions about the handover and other details of the case to the defence ministry.

“The handling of this incident shows that the Chinese and U.S. militaries have quite smooth communication channels. We think that this communication channel is beneficial to timely communication and the handling of sudden incidents and prevention of miscalculations and misunderstandings,” she said.

“As to what the U.S. defence department said, I have to verify it with the military. But I think what they said is
unreasonable as we have always said that for a long time the U.S. military has regularly sent ships and aircraft to carry out close up surveillance and military surveys in waters facing China, which threatens China’s sovereignty and security,” Hua told reporters.

“China is resolutely opposed to this and has always demanded the U.S. end these kinds of activities. I think this is the cause of this or similar incidents.”

The seizure has added to U.S. concern about China’s growing military presence and aggressive posture in the disputed South China Sea, including its militarization of maritime outposts.

China is deeply suspicious of any U.S. military activity in the resource-rich South China Sea, with state media and experts saying the use of the drone was likely part of U.S. surveillance efforts in the disputed waterway.

The U.S. Navy has about 130 such underwater drones, made by Teledyne Webb, each weighing about 60 kg (130 lb) and able to stay underwater for up to five months. They are used around the world to collect unclassified data about oceans, including temperature and depth.

It is not clear how many are used in the South China Sea.

(Editing by Paul Tait and Lincoln Feast)

China seizes U.S. underwater drone in South China Sea

The USNS Bowditch, an oceanographic survey ship, is seen in this undated U.S. Navy

By Phil Stewart

WASHINGTON (Reuters) – A Chinese warship has seized an underwater drone deployed by a U.S. oceanographic vessel in the South China Sea, triggering a formal diplomatic protest and a demand for its return, U.S. officials told Reuters on Friday.

The drone was taken on Dec. 15, the first seizure of its kind in recent memory, about 50 nautical miles northwest of Subic Bay off the Philippines just as the USNS Bowditch was about to retrieve the unmanned underwater vehicle (UUV), officials said.

“The UUV was lawfully conducting a military survey in the waters of the South China Sea,” one official said, speaking on condition of anonymity.

“It’s a sovereign immune vessel, clearly marked in English not to be removed from the water – that it was U.S. property,” the official said.

The Pentagon confirmed the incident at a news briefing and said the drone used commercially available technology and sold for about $150,000.

Still, the Pentagon viewed China’s seizure seriously since it had effectively taken U.S. military property.

“It is ours, and it is clearly marked as ours and we would like it back. And we would like this not to happen again,”  Pentagon spokesman Jeff Davis said.

Senator Ben Cardin, the top Democrat on the U.S. Senate Foreign Relations Committee, called the seizure “a remarkably brazen violation of international law.”

U.S. Navy Secretary Ray Maybus cited a “growing China” as one of the reasons that the Navy needed to expand its fleet to 355 ships, including 12 carriers, 104 large surface combatants, 38 amphibious ships and 66 submarines.

The seizure will add to concerns about China’s increased military presence and aggressive posture in the disputed South China Sea, including its militarization of maritime outposts.

It coincided with sabre-rattling from Chinese state media and some in its military establishment after U.S. President-elect Donald Trump cast doubt on whether Washington would stick to its nearly four-decades-old policy of recognizing that Taiwan is part of “one China.”

A U.S. research group this week said new satellite imagery indicated China has installed weapons, including anti-aircraft and anti-missile systems, on all seven artificial islands it has built in the South China Sea.

Mira Rapp-Hooper, a senior fellow in the Asia-Pacific Security Program at the Center for a New American Security, said China would have a hard time explaining its actions.

“This move, if accurately reported, is highly escalatory, and it is hard to see how Beijing will justify it legally,” Rapp-Hooper said.

SNATCHED AWAY

The drone was part of an unclassified program to collect oceanographic data including salinity, temperature and clarity of the water, the U.S. official added. The data can help inform U.S. military sonar data since such factors affect sound.

The USNS Bowditch, a U.S. Navy ship crewed by civilians that carries out oceanographic work, had already retrieved one of two of its drones, known as ocean gliders, when a Chinese Navy Dalang 3 class vessel took the second one.

Officials said the Bowditch was only 500 meters (yards) from the drone and, observing the Chinese intercede, used bridge-to-bridge communications to demand it be returned.

The Chinese ship acknowledged the communication but did not respond to the Bowditch’s demands, the Pentagon’s Davis said.

“The only thing they said after they were sailing off into the distance was: “we are returning to normal operations,” Davis said.

The United States issued the formal demarche, as such protests are known, through diplomatic channels and included a demand that China immediately return the drone. The Chinese acknowledged it but have not responded, officials said.

The seizure happened a day after China’s ambassador to the United States said Beijing would never bargain with Washington over issues involving its national sovereignty or territorial integrity.

“Basic norms of international relations should be observed, not ignored, certainly not be seen as something you can trade off,” Ambassador Cui Tiankai, speaking to executives of top U.S. companies, said on Wednesday.

He did not specifically mention Taiwan, or Trump’s decision to accept a telephone call from Taiwan’s president on Dec. 2.

The call was the first such contact with Taiwan by a U.S. president-elect or president since President Jimmy Carter switched diplomatic recognition from Taiwan to China in 1979, acknowledging Taiwan as part of “one China.”

(Reporting by Phil Stewart; editing by James Dalgleish and Grant McCool)

China installs weapons systems on artificial islands

A satellite image shows what CSIS Asia Maritime Transparency Initiative says appears to be anti-aircraft guns and what are likely to be close-in weapons systems (CIWS) on the artificial island Subi Reef in the South China Sea in this image released on December

By David Brunnstrom

WASHINGTON (Reuters) – China appears to have installed weapons, including anti-aircraft and anti-missile systems, on all seven of the artificial islands it has built in the South China Sea, a U.S. think tank reported on Wednesday, citing new satellite imagery.

The Asia Maritime Transparency Initiative (AMTI) said its findings come despite statements by the Chinese leadership that Beijing has no intention to militarize the islands in the strategic trade route, where territory is claimed by several countries.

AMTI said it had been tracking construction of hexagonal structures on Fiery Cross, Mischief and Subi reefs in the Spratly Islands since June and July. China has already built military length airstrips on these islands.

“It now seems that these structures are an evolution of point-defense fortifications already constructed at China’s smaller facilities on Gaven, Hughes, Johnson, and Cuarteron reefs,” it said citing images taken in November and made available to Reuters.

“This model has gone through another evolution at (the) much-larger bases on Fiery Cross, Subi and Mischief reefs.”

Satellite images of Hughes and Gaven reefs showed what appeared to be anti-aircraft guns and what were likely to be close-in weapons systems (CIWS) to protect against cruise missile strikes, it said.

Images from Fiery Cross Reef showed towers that likely contained targeting radar, it said.

AMTI said covers had been installed on the towers at Fiery Cross, but the size of platforms on these and the covers suggested they concealed defense systems similar to those at the smaller reefs.

“These gun and probable CIWS emplacements show that Beijing is serious about defense of its artificial islands in case of an armed contingency in the South China Sea,” it said.

“Among other things, they would be the last line of defense against cruise missiles launched by the United States or others against these soon-to-be-operational air bases.”

AMTI director Greg Poling said AMTI had spent months trying to figure out what the purposes of the structures was.

“This is the first time that we’re confident in saying they are anti-aircraft and CIWS emplacements. We did not know that they had systems this big and this advanced there,” he told Reuters.

“This is militarization. The Chinese can argue that it’s only for defensive purposes, but if you are building giant anti-aircraft gun and CIWS emplacements, it means that you are prepping for a future conflict.

“They keep saying they are not militarizing, but they could deploy fighter jets and surface-to-air missiles tomorrow if they wanted to,” he said. “Now they have all the infrastructure in place for these interlocking rings of defense and power projection.”The report said the installations would likely back up a defensive umbrella provided by a future deployment of mobile surface-to-air missile (SAM) platforms like the HQ-9 system deployed to Woody Island in the Paracel Islands, farther to the north in the South China Sea.

It forecast that such a deployment could happen “at any time,” noting a recent Fox News report that components for SAM systems have been spotted at the southeastern Chinese port of Jieyang, possibly destined for the South China Sea.

China has said military construction on the islands will be limited to necessary defensive requirements.

The United States has criticized what it called China’s militarization of its maritime outposts and stressed the need for freedom of navigation by conducting periodic air and naval patrols near them that have angered Beijing.

U.S. President-elect Donald Trump, who takes office on Jan. 20, has also criticized Chinese behavior in the South China Sea while signaling he may adopt a tougher approach to China’s assertive behavior in the region than President Barack Obama.

(Reporting by David Brunnstrom; Editing by Lisa Shumaker)

U.S. ready to confront Beijing on South China Sea: admiral

Guided missile destroyer in South China Sea

By Colin Packham

SYDNEY (Reuters) – The United States is ready to confront China should it continue its overreaching maritime claims in the South China Sea, the head of the U.S. Pacific fleet said on Wednesday, comments that threaten to escalate tensions between the two global rivals.

China claims most of the resource-rich South China Sea through which about $5 trillion in ship-borne trade passes every year. Neighbors Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims.

The United States has called on China to respect the findings of the arbitration court in The Hague earlier this year which invalidated its vast territorial claims in the strategic waterway.

But Beijing continues to act in an “aggressive” manner, to which the United States stands ready to respond, Admiral Harry Harris, head of the U.S. Pacific Command, said in a speech in Sydney.

“We will not allow a shared domain to be closed down unilaterally no matter how many bases are built on artificial features in the South China Sea,” he said. “We will cooperate when we can but we will be ready to confront when we must.”

The comments threaten to stoke tensions between the United States and China, already heightened by President-elect Donald Trump’s decision to accept a telephone call from Taiwan’s president on Dec. 2 that prompted a diplomatic protest from Beijing.

Asked about Harris’s remarks, Chinese Foreign Ministry spokesman Geng Shuang said the situation in the South China Sea was currently stable, thanks to the hard work of China and others in the region.

“We hope the United States can abide by its promises on not taking sides on the sovereignty dispute in the South China Sea, respect the efforts of countries in the region to maintain peace and stability in the South China Sea region and do more to promote peace and stability there,” he told a daily news briefing.

The United States estimates Beijing has added more than 3,200 acres (1,300 hectares) of land on seven features in the South China Sea over the past three years, building runways, ports, aircraft hangars and communications equipment.

In response, the United States has conducted a series of freedom-of-navigation operations in the South China Sea, the latest of which came in October.

The patrols have angered Beijing, with a senior Chinese official in July warning the practice may end in “disaster”.

Harris said it was a decision for the Australian government whether the U.S. ally should undertake its own freedom-of-navigation operations, but said the United States would continue with the practice.

“The U.S. fought its first war following our independence to ensure freedom of navigation,” said Harris. “This is an enduring principle and one of the reasons our forces stand ready to fight tonight.”

(Additional reporting by Ben Blanchard in Beijing; Editing by Lincoln Feast and Jacqueline Wong)

Exclusive: Risking Beijing’s ire, Vietnam begins dredging on South China Sea reef

Vietnam begins building in South China Sea

By Lincoln Feast and Greg Torode

SYDNEY/HONG KONG (Reuters) – Vietnam has begun dredging work on a disputed reef in the South China Sea, satellite imagery shows, the latest move by the Communist state to bolster its claims in the strategic waterway.

Activity visible on Ladd Reef in the Spratly Islands could anger Hanoi’s main South China Sea rival, Beijing, which claims sovereignty over the group and most of the resource-rich sea.

Ladd Reef, on the south-western fringe of the Spratlys, is completely submerged at high tide but has a lighthouse and an outpost housing a small contingent of Vietnamese soldiers. The reef is also claimed by Taiwan.

In an image taken on Nov. 30 and provided by U.S.-based satellite firm Planet Labs, several vessels can be seen in a newly dug channel between the lagoon and open sea.

While the purpose of the activity cannot be determined for certain, analysts say similar dredging work has been the precursor to more extensive construction on other reefs.

“We can see that, in this environment, Vietnam’s strategic mistrust is total … and they are rapidly improving their defences,” said Trevor Hollingsbee, a retired naval intelligence analyst with Britain’s defence ministry.

“They’re doing everything they can to fix any vulnerabilities – and that outpost at Ladd Reef does look a vulnerability.”

Reuters reported in August that Vietnam had fortified several islands with mobile rocket artillery launchers capable of striking China’s holdings across the vital trade route.

Vietnam’s foreign ministry did not respond to a request for comment.

The vessels at Ladd Reef cannot be identified in the images, but Vietnam would be extremely unlikely to allow another country to challenge its control of the reef.

Greg Poling, a South China Sea expert at Washington’s Center for Strategic and International Studies (CSIS), said it remained unclear how far the work on Ladd Reef would go. Rather than a reclamation and a base, it could be an attempt to simply boost access for supply ships and fishing boats.

Ladd could also theoretically play a role in helping to defend Vietnam’s nearby holding of Spratly Island, where a runway is being improved and new hangars built, he said.

“Vietnam’s knows it can’t compete with China but it does want to improve its ability to keep an eye on them,” Poling said.

Vietnam has long been fearful of renewed Chinese military action to drive it off its 21 holdings in the Spratlys – worries that have escalated amid Beijing’s build-up and its anger at the recent Philippines legal action challenging its claims.

China occupied its first Spratlys possessions after a sea battle against Vietnam’s then weak navy in 1988. Vietnam said 64 soldiers were killed as they tried to protect a flag on South Johnson reef – an incident still acutely felt in Hanoi.

BUILDING BURST

The United States has repeatedly called on claimants to avoid actions that increase tensions in the South China Sea, through which some $5 trillion in world trade is shipped every year.

Vietnam has emerged as China’s main rival in the South China Sea, actively asserting sovereignty over both the Paracel and the Spratly groupings in their entirety and undergoing its own naval modernisation. Taiwan also claims both, but its position is historically aligned with Beijing’s.

The Asia Maritime Transparency Initiative, run by the CSIS, says Vietnam has added about 120 acres (49 hectares) of land to its South China Sea holdings in recent years.

Regional military attaches say Vietnam’s key holdings are well fortified, some with tunnels and bunkers, appearing geared to deterring easy invasion.

Vietnam’s reclamation work remains modest by Chinese standards, however.

The United States, which has criticized China for militarizing the waterway, estimates Beijing has added more than 3,200 acres (1,300 hectares) of land on seven features in the South China Sea over the past three years, building runways, ports, aircraft hangars and communications equipment.

Beijing says it is entitled to “limited and necessary self-defensive facilities” on its territory and has reacted angrily to “freedom of navigation” operations by U.S. warships near Chinese-held islands.

CHINESE RECLAMATION WORK DAMAGED

In another image provided by Planet Labs, reclamation work in the Chinese-held Paracel Island chain appears to have been damaged by recent storms.

China began dredging and land filling earlier this year at North Island, about 12 km (7 miles) north of Woody Island, where it has a large military base and this year stationed surface-to-air missiles.

Satellite images in February and March showed dredging vessels working to build a 700 meter (2,300 ft) sand bridge connecting low-lying North Island with neighboring Middle Island.

But images taken after two powerful storms spun through the region in October show the narrow sand strip has been largely swept away.

The Paracels have been under Chinese control for more than 40 years after a battle towards the end of the Vietnam War, when Chinese forces removed the then-South Vietnamese navy. Analysts say they play a key part in protecting China’s nuclear armed submarine fleet on Hainan Island, to the north.

China has not commented publicly on the work at North Island and the foreign ministry did not respond to requests for comment.

(Additional reporting by Martin Petty and Ben Blanchard; Editing by Alex Richardson)