U.S. President Donald Trump's administration is ending most, if not all, remaining U.S. aid for Afghanistan and Yemen, aid sources said on Monday, in what the U.N. World Food Programme said could be "a death sentence" for millions.

The cuts were among numerous aid programs terminated for more than a dozen countries - including Somalia and Syria - over the weekend by the State Department and U.S. Agency for International Development, according to Sarah Charles, a former head of USAID's humanitarian affairs bureau, and nine sources, including six current U.S. officials involved in humanitarian aid who spoke on condition of anonymity.

The total amount of aid cut was over $1.3 billion, according figures provided by Stand Up For Aid, a grassroots advocacy group. That includes $562 million for Afghanistan, $107 million for Yemen, $170 million for Somalia, $237 million for Syria and $12 million for Gaza.

The U.N. World Food Programme warned that the termination of U.S. funding for emergency food assistance "could amount to a death sentence for millions of people facing extreme hunger and starvation," and said it was in contact with the Trump administration for more information.

In a Post on X, WFP chief Cindy McCain said funding cuts "will deepen hunger, fuel instability, and make the world far less safe."

A State Department spokesperson referred Reuters to the White House when asked about the program terminations. The White House did not immediately respond to a request for comment. U.N. spokesperson Stephane Dujarric said the U.N. was trying to get details on the canceled contracts.

The cuts are the latest piece of the Trump administration's drive to dismantle USAID, the main U.S. humanitarian aid agency. His administration has canceled billions of dollars in life-saving programs since the Republican president began his second term on January 20.

Many of the terminated programs had been granted waivers by U.S. Secretary of State Marco Rubio from cuts to foreign aid programs made by billionaire Elon Musk's Department of Government Efficiency since February, three of the sources said.

The U.S. has been the largest aid donor to Taliban-ruled Afghanistan and to Yemen, most of which is controlled by Islamist militants of the Iran-backed Houthi movement. Both countries have suffered years of devastating war.

"Every remaining USAID award for Afghanistan was terminated," said one source. The officials said the canceled funds included assistance for a U.N. agency that helps women and girls, the WFP and at least six non-governmental organizations.

Assistance to Afghans provided by the State Department's Bureau of Population, Refugees and Migration also was terminated, five sources said.