The head of the World Food Program says the U.N. agency is confronting its worst challenge since World War II in trying to tackle five top-level humanitarian crises at the same time.

Ertharin Cousin said in an interview Friday with The Associated Press that the five crises — in Syria, Iraq, Central African Republic, South Sudan, and the Ebola epidemic in West Africa — require large-scale operations by WFP and other humanitarian agencies.

In addition, she said, WFP is doing preparatory work for a potential scale-up in food assistance to four other countries where there is growing political instability — Yemen, Nigeria, Ukraine and Libya.

Cousin said the demands are overwhelming the donor community and as a result WFP had to cut food assistance to six million Syrians in January.