The UN has warned there will be many deaths in Kenya if immediate food aid is not delivered to 3.5 million people facing the threat of starvation.
A UN visit to El Wak highlighted Kenya's crisis
Head of the UN World Food Programme James Morris said 11 million were at risk across the Horn of Africa.
At least 40 people have died in northern Kenya with cattle, camels and donkeys also dying at a worrying rate.
Five years of drought have created the worst situation in the region for four decades, the United Nations says.
Mr Morris said after visiting El Wak on the Kenya-Somalia border that the world needed to wake up to the problem.
"The world has not appreciated in the last 60 days how serious this situation is... we are now in a crisis. We are in a life-saving mode," he said.
He said unless a donation shortfall of $189m (£107m) was met soon, many deaths from malnutrition would inevitably follow.
UN stocks of maize and rice would only last to the end of next month and the stocks of beans and vegetable oil were far worse, Mr Morris said.
"These people now have nothing. They will have to be provided with food," he said.
The situation in Somalia was equally alarming, the WFP head said. He urged rival militias in the country "to set aside their differences and guarantee safe passage [of food aid] to prevent a humanitarian catastrophe".
British charity Christian Aid has echoed the starvation threat, saying the risk was spread across much of the Horn of Africa.
Dominic Nutt, the charity's emergencies specialist, said: "This is a crisis on the verge of becoming a catastrophe.
"There are dead cattle everywhere and people have sold everything they have to buy food.
"These are the last few weeks that many people are going to be able to survive without help."
The charity said that although drought was the cause of the immediate crisis, reducing poverty in the region was the underlying concern.
The drought affecting Kenya has been declared a "national disaster" by President Mwai Kibaki.
The UK announced last week it was giving Kenya an extra £15m ($26m) in humanitarian assistance.