“The aid operation in Yemen continues to be seriously underfunded,” the UN body said in a statement.
As an example, it cited an international summit held last month to raise funds to meet the urgent humanitarian needs of millions of Yemenis.
Some 1.3 billion dollars were pledged at the event, less than a third of the 4.3 billion needed to maintain aid programs in 2022, it stressed.
It noted that lack of funding has forced UNFPA to scale back life-saving reproductive health and protection interventions in Yemen since the beginning of the year.
The agency warned that 23.4 million Yemenis, 75 percent of the population, will require some form of humanitarian assistance in 2022.
More than 4.3 million people were displaced from their homes, the economy collapsed, as did the health system, the agency stressed.
The United Nations Office for the Coordination of Humanitarian Affairs stated in a recent report that 19 million Yemenis require food aid and 21.9 million support to access critical health services.