"More and more people need help in the Horn (of Africa) and we're now on high alert over the impact of the March to May long rains," WFP Director Josette Sheeran said in a statement.
The WFP estimates that it delivers food aid to more than 5 million people in the Horn of Africa who struggle to cope with regional conflict, drought and soaring food prices.
At least 1 million people were pushed into hunger when a drought in October struck the eastern parts of the region.
Food prices have increased by as much as 120 percent in parts of the Horn of Africa.
"The outlook for the rains in eastern parts of the Horn (of Africa) is worrying, especially combined with rising food and fuel prices and conflict," said Sheeran. "If the latest meteorological forecasts of below-normal long rains in the eastern Horn (of Africa) are correct, the crisis will worsen in those areas and more people will go hungry."