Food aid will be cut for more than a million hungry Nigerians affected by Boko Haram's insurgency if promised funding from the international community doesn't arrive, according to a United Nations official.

Peter Lundberg, the deputy U.N. humanitarian coordinator in Nigeria, wrote in the French newspaper Le Monde that just 15 percent of the U.N. aid appeal for one of the world's worst humanitarian crises has been received. Over the next six months, $242 million is needed to help 1.8 million people, he said.

"Without sufficient financing, the World Food Program will have to reduce its vital support," he wrote Friday.

A half-million children in northeast Nigeria are suffering from severe malnutrition, Lundberg said. "Without treatment, one in five will die," he said.

WFP's Nigeria office did not respond to a request for more details on what aid would be cut and when.

Nigeria is part of what the U.N. has called the largest humanitarian crisis since the world body was founded in 1945, with more than 20 million people in four countries facing possible famine. The other nations are South Sudan, Somalia and Yemen.

Lundberg said the U.N. has appealed for $1 billion in aid this year for Nigeria, where an estimated 4.7 million people in the northeast are in urgent need of food aid.

Nigeria's military has been fighting to win back areas that have been under the control of the Boko Haram extremist group. The years-long radical insurgency in the vast northeast has disrupted both markets and farming, creating the hunger crisis.

As President Donald Trump seeks to cut foreign aid under the slogan of "America First," two U.S. senators are proposing making American food assistance more efficient after meeting with victims of South Sudan's famine and civil war.

Following a visit to the world's largest refugee settlement in northern Uganda with the Republican chairman of the Senate Foreign Relations Committee, Democratic Sen. Chris Coons of Delaware told The Associated Press on Saturday that the U.S. "can deliver more food aid at less cost" through foreign food aid reform.

The United States spent roughly $2.8 billon in foreign food aid last year and is the world's largest provider of humanitarian assistance. But current regulations require most food aid to be grown in the U.S. and shipped under an American flag.

he U.N. says South Sudan is part of the largest humanitarian crisis since World War II, with roughly 20 million people there and in Somalia, Nigeria and Yemen facing possible famine. Two counties in South Sudan were declared famine areas in February.

The senators watched as South Sudanese divided sacks of corn and cereals during a food distribution. Behind them, snaking lines of refugees waited for their rations of food that last for 40 days.

The Bidi Bidi settlement is a sprawling complex of mud-brick houses that hold some of the world's most desperate people. With little respite from the fierce sun, arguments broke out at the food distribution site.

"We don't have enough food," said Madra Dominic, one of the waiting refugees. "Right now they are reducing (food)." Uganda's government has said it is near "breaking point" and that there could be serious food shortages if more outside aid doesn't arrive.

In March, Trump proposed a budget that would cut 28 percent of funding for diplomacy and foreign aid, singling out the Food for Peace program that funds a majority of U.S. foreign food assistance.