Children sit on sacks as scavengers sort for recyclable plastic materials at the Dandora dumping site on the outskirts of Nairobi, Kenya. [Reuters]

U.N. aid chief Martin Griffiths said on Tuesday that close to 2 million children are at risk of starving to death as the Horn of Africa faces one of its worst droughts in decades.

Parts of Kenya, Ethiopia, and Somalia are suffering their driest conditions in more than 40 years and aid agencies are seeking to avoid the repeat of a famine a decade ago that killed hundreds of thousands of people. 

Addressing a closed-door donor conference held in Geneva, Griffiths said the organisation had only a fraction of the money it needs to respond to the drought. However, at the same event donors pledged nearly the entire budget amount of $1.4 billion, he said later on Twitter, thanking them for their generosity.

"Let's not lose the sense of urgency to act," he said. Earlier, he had acknowledged that the Ukraine conflict risks diverting the world's attention and finances.

The European Union, which co-hosted the event, announced 633 million euros ($674.40 million)to boost food security for the region and Canada announced $73 million in funding, according to statements sent to Reuters.

A fourth failed rainy season in the region is now a growing probability creating what Griffiths said would constitute "one of the worst climate-induced emergencies in its history."

Already, more than 15 million people in the region are experiencing high hunger levels and herders have lost some 3 million animals due to drought, he added in the same speech.

The U.N.'s Intergovernmental Panel on Climate Change, the top global climate science authority, said heatwaves, droughts and extreme rainfall would become more frequent in coming decades as temperatures continue to climb. 

($1 = 0.9386 euros)