By Ben Blanchard

BEIJING (Reuters) – China welcomes all countries to a forum this weekend on China’s new Silk Road plan, the foreign ministry said on Saturday, after the United States warned China that North Korea’s attendance could affect other countries’ participation.

Two sources with knowledge of the situation said the U.S. embassy in Beijing had submitted a diplomatic note to China’s foreign ministry, saying inviting North Korea sent the wrong message at a time when the world was trying to pressure it over its repeated missile and nuclear tests.

The disagreement over North Korea threatens to overshadow China’s most important diplomatic event of the year for an initiative championed by President Xi Jinping.

Asked about the U.S. note, the foreign ministry said in a short statement sent to Reuters that it did “not understand the situation”.

“The Belt and Road initiative is an open and inclusive one. We welcome all countries delegations to attend the Belt and Road Forum for International Cooperation,” it said.

The ministry did not elaborate. It said on Tuesday North Korea would send a delegation to the summit but gave no other details.

The United States is sending a delegation led by White House adviser Matt Pottinger.

Despite Chinese anger at North Korea’s repeated nuclear and missile tests, China remains the isolated state’s most important economic and diplomatic backer, even as Beijing has signed up for tough U.N. sanctions against Pyongyang.

China has over the years tried to coax North Korea into cautious, export-oriented economic reforms, rather than sabre rattling and nuclear tests, but to little avail.

China has not announced who North Korea’s chief delegate will be, but South Korea’s Yonhap news agency said Kim Yong Jae, North Korea’s minister of external economic relations, would lead the delegation.

‘MISGIVINGS’

Leaders from 29 countries will attend the forum in Beijing on Sunday and Monday, an event orchestrated to promote Xi’s vision of expanding links between Asia, Africa and Europe underpinned by billions of dollars in infrastructure investment.

Delegates will hold a series of sessions on Sunday to discuss the plan in more detail, including trade and finance. China has given few details about attendees.

Some Western diplomats have expressed unease about both the summit and the plan as a whole, seeing it as an attempt to promote Chinese influence globally.

China has rejected criticism of the plan and the summit, saying the scheme is open to all, is a win-win and aimed only at promoting prosperity.

Zhang Junkuo, deputy director general of cabinet think-tank the State Council Development Research Centre told reporters there were “misgivings, misinterpretations and misunderstandings” about the initiative.

“We must increase communication and exchanges so as to broaden our areas of cooperation and consolidate the basis for cooperation,” Zhang said.

In an English-language commentary on Saturday, China’s state-run Xinhua news agency said the new Silk Road, officially called the Belt and Road initiative, would be a boon for developing countries that had been largely neglected by the West.

“As some Western countries move backwards by erecting ‘walls’, China is contriving to build bridges, both literal and metaphorical. These bridges are China’s important offering to the world, and a key route to improving global governance,” it said.

Some of China’s most reliable allies and partners will attend the forum, including Russian President Vladimir Putin, Pakistani Prime Minister Nawaz Sharif, Cambodian Prime Minister Hun Sen and Kazakh President Nursultan Nazarbayev.

There are also several European leaders coming, including the prime ministers of Spain, Italy, Greece and Hungary.

Xi offered Prime Minister Alexis Tsipras of deeply indebted Greece strong support on Saturday, saying the two countries should expand cooperation in infrastructure, energy and telecommunications.

(Additional reporting by Elias Glenn; Editing by Eric Meijer, Robert Birsel)