As the United Nations marks its 80th anniversary, its humanitarian operations are increasingly in doubt.

The deputy executive director of the U.N. World Food Program has been on whirlwind visits to hotspots in the Middle East and Sudan to assess dire humanitarian situations and escalating demands for food from millions of people trapped or fleeing conflicts.

At least one quarter of Gaza’s population – 576,000 people – are one step away from famine and virtually the entire population desperately needs food resulting in some aid trucks being shot at, looted and overwhelmed by hungry people, top U.N. officials say.

A halted landmark grain deal that allowed Ukrainian grain to flow to countries in Africa, the Middle East and Asia is rattling the operations of the United Nations food agency, its deputy executive director said.

The United Nations says it has been forced to cut food, cash payments and assistance to millions of people in many countries because of “a crippling funding crisis” that has seen its donations plummet by about half as acute hunger is hitting record levels.