United Nations aid workers in Yemen say they will be asking for more than $2.4 billion at an international pledging conference Tuesday in Saudi Arabia.
Humanitarian officials on the ground say the coronavirus is making what was already a dire situation in one of the world's poorest nations even worse.
The pandemic, along with the dangers of getting caught up in the fighting between Saudi-led forces and Iranian-backed Houthi rebels, has forced the U.N. to shut down or cut 75% of its programs in Yemen and slash food rations, according to the Associated Press.
"It's almost impossible to look a family in the face, to look them in the eyes and say, 'I'm sorry but the food that you need in order to survive we have to cut in half,'" U.N. Coordinator for Yemen Lise Grande says.
There are also reports of coronavirus patients being turned away from hospitals because Yemen's barely functioning health care system may not be able to handle a large number of cases, officials say.
The U.N. reports that 20% of Yemenis who come down with COVID-19 die compared with the global average of 7%.
The U.N. has accused the Houthi rebels, who control the Yemeni capital of Sanaa, of underreporting the number of coronavirus cases - a charge the Houthis deny.
Grande tells AP that the Houthis have promised to be more forthcoming - a move she hopes will encourage more donors to step up and pledge at Tuesday's conference.
The U.N. says 80% of Yemeni civilians need food aid or face starvation.
A Saudi-led coalition to drive the Houthis out of Yemen has included airstrikes that sometimes hit civilian neighborhoods, including hospitals and schools.
The Houthis control the capital, but under a December peace deal, they have been pulling back from Red Sea ports, U.N. monitors say.
Yemeni officials accuse the rebels of bluffing and say they are actually handing over control to their own men dressed in different uniforms to fool the observers.