A former USAID official said the consequence could be one million children not receiving treatment for severe malnutrition, resulting in 163,500 additional deaths per year globally.
The World Food Programme, which supports just under 200,000 Kakuma refugees, told AFP they had cut rations, delivered as food and cash, to 40 percent of their previous level.
President Donald Trump and ally Elon Musk have hit foreign aid harder and faster than almost any other target in their push to cut the size of the federal government.
The school run by the Future Prowess Islamic Foundation has benefited 3,000 children in Borno state, the epicenter of the 16-year conflict with Boko Haram that has displaced and orphaned many.