The aid agency, Oxfam, has warned of a shortfall of 68% in the pledges received after an appeal by UN agencies for aid to halt a famine in drought-stricken East Africa.
Hunger has already claimed the lives of hundreds of people and tens of thousands of livestock in one of the region's worst droughts in years after rains failed last November.
Kenya, Somalia and Ethiopia are the worst affected countries in a crisis that threatens 11 million people.
Oxfam said that firm commitments from richer countries to fund the response to the food crisis were not being made quickly enough.
The agency said that €156 million had been pledged to the appeal for €482m so far, leaving a shortfall of €327m.
In Kenya, where the United Nations says 3.5 million people are at risk, just 8.3% of the funds needed have been pledged. Somalia had commitments to 17% of the aid requested, while only Ethiopia was near to meeting its target of €146m, the agency said.
Oxfam said malnutrition rates in northern Kenya were more than double the 15% level at which an emergency is declared.
