British charity Christian Aid has echoed fears of starvation, saying the risk has 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."
Head of the UN World Food Programme James Morris said 11 million are at risk across the Horn of Africa.
"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.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.
Head of the UN World Food Programme, James Morris
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, Morris said.
The government of Kenya has declared the famine affecting numerous parts of the country a ‘national disaster’ and has called for national and international efforts to raise much needed aid to provide food for about 3.5 million people, almost 10 percent of the population, over the next six months, according to Action by Churches Together (ACT) International.
Keith Wright of Food for the Hungry International’s (FHI) says, "It's accelerating as people lose more and more livestock. That's really what they rely on for food, and as they die they really run out of resources quickly when that happens. So, what we're seeing, unfortunately, the situation getting worse every day," says Wright.
Meanwhile, the situation in Somalia is equally alarming, Morris 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".
