The Ethiopian government needs emergency food aid for 6.2 million people due to prolonged drought.
There is a food crisis in a large part of East Africa and the Horn, where it is suggested that 23 million people in seven countries are under threat.
The UN's World Food Programme says Ethiopia will need $US285 million in the next six months.
On its website, it says more than 10 million people in total are affected by drought in Ethiopia.
The BBC reports only 17% of Ethiopia's 80 million people live in urban areas.
There have been four years of bad harvests. The WFP says the
problem is compounded by high food costs: cereal prices have doubled on many markets.
Last month, Oxfam launched a $US15 million emergency appeal for the whole East African region.
In a report marking 25 years since the famine that killed around one million people in Ethiopia, Oxfam said imported food aid saves lives in the short term, but does little to help communities withstand the next shock.
The report, named Band Aids and Beyond, called for a new approach focused on preparing communities to prevent and deal with disasters before they strike.