Kenya has mobilised its military, police and national youth service to distribute food, water and medicines to areas hit hardest by drought.
The government estimates that at least 10 million Kenyans - one third of the population - is in need of food aid.
An emergency cabinet meeting also decided to keep schools open through the current holidays so the food programme could continue.
Many farmers have abandoned villages in search of water and pasture for cattle.
The BBC reports drought and high global food prices, combined with last year's post-election violence has contributed to the crisis.
Government measures introduced earlier this year to allow duty-free maize imports and subsidised fertiliser failed to ease the situation.
Meanwhile, the United Nations Food and Agricultural Organisation says a giant herd of cattle have been driven across the border in northern Kenya into the Borena zone in Ethiopia by farmers in search of scarce pastures.
The FAO says it is one of the largest movements of cattle in a decade. The herd numbers more than 200,000.
Power supply also hit
The drought has also hit Kenya's capacity to generate hydro-electricity, with electricity rationing introduced last week.
In January, President Mwai Kibaki said 10 million Kenyans were facing starvation.
He said this was due to drought and the effects of post-election violence, which forced thousands of farmers from their lands.