"The funding shortfall is so severe that we will have to start reducing the size of rations early next month -- the hardship people are facing is going from bad to worse," U.N. World Food Program Executive Director Josette Sheeran said in a release.
In parts of central Kenya, drought and rising food prices have combined to create a continuing famine.
"Drought has left farmers with empty fields and the carcasses of dead cattle litter the land in some of the worst affected areas," Sheeran said.
Up to 50 percent of shallow wells, boreholes and other water sources are dry.
Malnutrition rates are rising as staple food prices have doubled.
Coupled with that, the food agency said it has received just 8 percent of the $301 million needed to feed 3.8 million people during the next six months.