By Tom Miles

GENEVA (Reuters) – The Saudi-led military coalition must fully lift its blockade on Yemen, where seven or eight million are “right on the brink of famine”, U.N. humanitarian chief Mark Lowcock said on Friday, but he declined to say if maintaining such a blockade was legal.

“That blockade has been partially wound down but not fully wound down. It needs to be fully wound down if we are to avoid an atrocious humanitarian tragedy involving the loss of millions of lives, the like of which the world has not seen for many decades,” he said.

The coalition, fighting the armed Houthi movement in Yemen with backing from the United States, Britain and other countries, eased the blockade this week, allowing aid ships into the Red Sea ports of Hodeidah and Salif, as well as U.N. flights to Sanaa.

U.N. humanitarian officials have said Yemen cannot rely on humanitarian aid alone but must have commercial imports too, because it relies on imports for the vast majority of its food, fuel and medicine.

The coalition wants tighter U.N. verification and inspection for commercial ships entering the Houthi-controlled port of Hodeidah, the most important hub.

“I’ve called for five things in respect of the Saudi blockade,” Lowcock said. “Some of them have happened like the resumption of humanitarian air services, like partial reopening of the ports of Hodeidah and Saleef on the Red Sea. What I’m interested in is finding solutions.”

According to a 2015 U.N. Security Council resolution on Yemen, “arbitrary denial of humanitarian access and depriving civilians of objects indispensable to their survival, including wilfully impeding relief supply and access, may constitute a violation of international humanitarian law.”

Lowcock, launching the U.N.’s humanitarian appeal for 2018, declined to say if Saudi Arabia and its partners were in breach of the law, but said the world body had consistently called on all sides to uphold their obligations.

“It is absolutely essential that people uphold their international obligations. Wars have rules and they need to be complied with,” he said.

“I’m not a lawyer but clearly international humanitarian law includes a requirement to facilitate unhindered access for aid agencies, and that’s what I’ve been trying to secure both in what I’ve said publicly and also in my private dialogue,” he told Reuters.

(Reporting by Tom Miles; Editing by Alison Williams, William Maclean)