Yemen must not become a forgotten crisis behind Ukraine, organisers of Wednesday's UN pledging conference said, warning of catastrophic hunger if donations were not forthcoming.
The United Nations considers war-torn Yemen as the world's worst humanitarian disaster -- but the money preventing the situation from getting worse is now running out, they warned.
"Today we are meeting to plug a huge gap in funding for the life-saving response," UN humanitarian chief Martin Griffiths told reporters.
"The war is in its seventh year and counting. The economy lies in ruins. Basic services are collapsing," he added.
"This year's response needs nearly $4.3 billion to help over 17 million people across Yemen."
As funding had been drying up since late last year, aid agencies were being forced to cut back or stop food and health services, he said.
"Today we hope to raise the money to replenish the food pipeline, stock up health clinics and provide shelter to the displaced.
"And to send a message to the people in Yemen that we do not forget them," said Griffiths.
The British diplomat said Russia's full-scale invasion of Ukraine, launched last month, would have far-reaching secondary impacts.
It will "surely harm the lives of many Yemenis", he said, given that the country depends almost entirely on food imports, with nearly a third of its wheat supplies coming from Ukraine.
Out of 31.9 million people in Yemen, 23.4 million were in need of humanitarian assistance, of which 12.9 million were in acute need, said the UN.
Yemen has been wracked by a devastating war since 2014, pitting the Iran-backed Huthi rebels against the internationally recognised government, supported by a Saudi-led military coalition.
Hundreds of thousands of people have been killed directly and indirectly in the war, and millions have been displaced.
'Teetering on the edge' - The World Food Programme (WFP) said the levels of hunger could become catastrophic if the Ukraine crisis pushed up food prices.
Wednesday's pledging event is being co-hosted by the UN humanitarian agency, Switzerland and Sweden.
"As of course Ukraine keeps us very much busy and is a huge concern, it is crucial that no other crisis becomes a forgotten crisis," said Manuel Bessler, Switzerland's humanitarian aid chief.
The humanitarian situation is poised to worsen between June and December, the Food and Agriculture Organization, WFP and the UNICEF children's agency said in a joint statement.
"Yemen's already dire hunger crisis is teetering on the edge of outright catastrophe, with 17.4 million people now in need of food assistance and a growing portion of the population coping with emergency levels of hunger," the three UN agencies warned.
WFP said the number of people needing food assistance had increased by 1.2 million over the past year -- and is forecast to reach 19 million people in the second half of 2022.
"We are looking at a seismic hunger crisis if we do not step up now," said WFP executive director David Beasley.
"Funding for Yemen has never reached this point. We have no choice but to take food from the hungry to feed the starving."