The UN emergency food aid agency needs $1 billion to feed 20 million people in east Africa over the next six months, it said.
Around half of that money is needed for Ethiopia alone, Ramiro Lopes da Silva, director of emergencies at the World Food Programme said on the sidelines of a UN summit on global hunger in Rome.
Drought, erratic rains and conflict have hurt crops and pastures in several countries in the region.
Kenya, east Africa’s biggest economy, is suffering from the worst drought in almost a decade.
The number of Ethiopians in need of emergency food aid has risen this year to 6.2 million, and Somalis are facing their worst humanitarian crisis in 18 years of conflict, with one in five children suffering from acute malnutrition.
“The needs have increased throughout the year, and we are now $1 billion short for the next six months,” da Silva told reporters.
Due to an overall funding shortfall this year, WFP says it has had to reduce operations and cut food rations in Kenya and Ethiopia.
The UN says cereal production in east Africa fell 6.3% in 2009, and the food import bill in the region, where food prices are the highest in Africa, is expected to reach around $4 billion.