Ethiopia’s government and aid agency leaders are revising upwards their joint $1.4 billion appeal for more than 10 million people hit by the country’s worst drought in 50 years.

“Surges in humanitarian needs are already registered since… December,” the United Nations Office for the Coordination of Humanitarian Affairs said.

“Considering the reported spike in need, the government and the Ethiopia Humanitarian Country Team agreed to update the HRD,” it said, referring to the Humanitarian Requirements Document, the original appeal launched in December.

The team is re-assessing so-called hotspot areas where hunger is worst and should complete their work in three weeks, the United Nations said.

The appeal is the third largest in the world after those for Syria and Yemen, and about half the $1.4 billion has been raised.

The number of farmers urgently needing seeds to plant during the rainy season has risen to 3.3 million from 2.2 million in December, and drought-affected people excluded from the December appeal have also been seeking food aid, the United Nations said.

The inadequate response to the original appeal means there is a shortage of food aid and malnutrition will increase dramatically if donor money runs out in May, the United Nations has said.