The United Nations food agency gave a warning on Tuesday that it may reduce food rations to millions of Yemenis from next month because of a lack of funding.
More than two thirds of Yemen's population are food insecure and the World Food Program provides aid to 11 million Yemenis. More than 8 million of them live in Houthi-controlled zones.
"WFP is facing a significant funding shortfall and without immediate contributions we will have to reduce food rations to millions of Yemenis from October," said Herve Verhoosel, the agency's senior spokesman.
The world body has said before that it has faced difficulties distributing aid across the country. It halted some aid in Sanaa on June 20 out of concern that food was being diverted from vulnerable people.
Reports surfaced last month that Houthi rebels destroyed tonnes of food aid they said had expired after it was held up for months in the war-torn country.
The agency said it needed more than over $600 million (Dh2.2 billon) to fund its work in Yemen for the next six months.
“We have a three to four month lead time in Yemen to import and then transport enough food to feed the millions in Yemen who rely on WFP assistance,” Mr Verhoosel said.
The UN official urged the international community to ensure a constant flow of “commodities coming in to Yemen to ensure that each month we can get food to the most vulnerable”.
WFP's average requirements are about $200m per month as the agency continues to scale up its operations to reach 12 million people monthly, he said.
From May through July, WFP reached more than 11 million people each month with food assistance.
The UAE and Saudi Arabia are the largest humanitarian donors to Yemen.
Last year, their joint pledge of $930m was given to the UN in single disbursement, the UAE's Minister of State for Foreign Relations, Dr Anwar Gargash, said in July.
The UAE’s total contribution to Yemen has exceeded $5.5 billion since 2015.
Mark Lowcock, the UN's undersecretary general for humanitarian affairs, praised the efforts made by the two states on Monday.
“I have just this morning received confirmation from the Saudi authorities that they plan on 25 September to transfer $500m in a single payment to my office in discharge of the pledge they made for the Yemen Humanitarian Response Plan in February,” he told the UN's Security Council.
The UAE has also allocated $200m to the response plan. "That includes $100m for the World Food Programme and an additional $100m channelled through my office for other urgent priorities," Mr Lowcock said.