The WFP fears that if rains fail, food shortages will get worse
More than 14 million people in the Horn of Africa need food aid because of drought and rocketing food and fuel prices, the United Nations has warned.
The UN World Food Programme says it urgently needs $400m (£200m) to prevent starvation in the east African region.
Ethiopia is worst hit, with 10 million people - some 12% of the population - in need of extra food supplies.
Somalia, Eritrea and Djibouti are also affected, along with northern parts of Kenya and Uganda.
Economic events outside Africa - which are driving up food and fuel prices - are exacerbating the crisis caused by a lack of water in the region.
The UN - backed by the main international aid non-governmental organisations - has warned of dire consequences for millions of people living in what a BBC correspondent says is a vulnerable region.
HORN OF AFRICA HUNGER
Ethiopia: 4.6m need emergency food support. Another 5.7m need extra food or cash
Somalia: 2.6m facing acute food shortages - could rise to 3.5m by end of 2008
Kenya: 1.2m need urgent food supplies
Uganda: 707,000 in dire need of food
Djibouti: 80,000 facing acute food shortages
Ethiopia has nearly exhausted its food reserves, the government having used stocks already in the hope that food prices would fall, making it cheaper to replenish its stores.
Instead, costs have risen further.
More expensive fuel means the costs of transporting and distributing food have soared, and the WPF says the local price of grain is nearly three times higher than it was a year ago.
In Somalia, 2.6m people were in need of food aid at the start of this year.
Mark Bowden, the UN's humanitarian co-ordinator for the region, projects that that figure will have risen sharply by the end of 2008.
"We're now estimating that by the end of the year 3.5m people will need assistance... which is a frightening figure to have to deal with," he said.
"People are reducing their food intake... we only have months before we go into a major crisis."
The WFP fears that if rains due in September and October fail, the situation will get even worse.
It says the current food shortages are worse than two years ago, when 11m people needed food aid.