Food aid to Sudan will dry up by the end of March unless fresh funding is secured, the United Nations warned Thursday, intensifying fears for millions trapped in what has become the world’s worst hunger crisis.

Nearly three years of brutal fighting between the Sudanese army and the paramilitary Rapid Support Forces have killed tens of thousands, displaced about 11 million people and repeatedly derailed efforts to restore peace.

Diplomatic initiatives led by the United States and regional mediators, Egypt, Saudi Arabia and the United Arab Emirates, collectively known as the Quad, have failed to produce a cease-fire, with both sides locked in a battle for territory.

Those stalled efforts were underscored Wednesday in Cairo, where senior officials from the Quad, alongside representatives of the United Nations, the European Union and regional bodies, met to assess the peace process, one that has so far yielded little tangible progress.

“By the end of March, we will have depleted our food stocks in Sudan,” said Ross Smith, director of emergency preparedness and response at the World Food Program.