The drought is adding to the humanitarian crisis in Ethiopia, where the war between government forces and the rebel Tigray People's Liberation Army (TPLF) in the north of the country has already left millions there in desperate need of aid.

The drought in the Somali, East and South Oromia regions is having a "devastating impact on the lives and livelihood of pastoralist and agro-pastoralist communities living in the area after the third consecutive failed rainy season", the UN Office for the Coordination of Humanitarian Affairs said in a statement posted online this week.

It said more than 6.4 million people in the afflicted areas were estimated to require food assistance this year, and that while the Ethiopian government and its humanitarian partners were working to tackle the crisis, "the response is not commensurate with the dire need."

About three million people in Somali and South Oromia were suffering from water shortages, while an unknown number have been forced from their homes.

Altogether, about 200,000 children and pregnant or lactating women were suffering from moderate malnutrition and 14,000 children acute malnutrition, it said.

Several hundred thousand livestock deaths have also been reported because of a lack of water and feed, according to the report.

In November, the UN's World Food Programme (WFP) said the number of people facing hunger across northern Ethiopia because of the conflict had surged to 9.4 million, in Tigray and also the neighbouring regions of Amhara and Afar.

In Tigray itself, which is under a de facto blockade, the United Nations has said that hundreds of thousands of people are living in famine-like conditions.