United Nations' agencies and aid groups are asking several countries for nearly $50m for relief work over the next three months.

The Ethiopian Government says it has asked for food stocks in critical areas, but knows of no firm promises of food aid after August.

One aid official said disastrous rain failures had put huge numbers of people on the brink of a precipice.

The BBC's Martin Dawes: Risk of a major humanitarian disaster

Correspondents say some countries will be wary about the appeal while Ethiopia continues spending $1m a day on its war with neighbouring Eritrea, but the UN is warning of the risk of a major humanitarian disaster.

A government official said that the drought and the war were two separate issues.

Third from bottom

The UN Human Development Report, released on Monday, showed that Ethiopia ranked 172 out of 174 countries for life expectancy, health care, education and income.