ADDIS ABABA, Ethiopia (AP) — The head of the African Union mission in Somalia says its planned withdrawal of 21,000 troops from the extremist-threatened Horn of Africa nation by 2020 cannot be met without urgent help from the international community.

Francisco Madeira told The Associated Press he fears all gains made in the past decade could be lost in an abrupt departure.

Speaking during an African Union summit, he says the world must "fast-track" to meet the 2020 goal of handing over security responsibilities to Somalia's military. "The U.N. and other partners must understand that this enterprise needs additional resources."

The U.S. military and others have warned that Somalia's forces are not ready.

The African Union pullout has begun, with 1,000 troops leaving last year. Madeira hopes another 1,000 troops will withdraw this year.