JOHANNESBURG, South Africa - Zimbabwe has collapsed, and the world must act now to keep it from deteriorating into Somalia-scale chaos, the top U.S. envoy for Africa said Thursday.

U.S. among Mugabe's critics
Zimbabwean President Robert Mugabe, in power since independence from Britain in 1980 and seen as increasingly autocratic, and the opposition have been deadlocked over a power-sharing agreement since September.

The political impasse comes amid a mounting economic and humanitarian crisis that has pushed thousands of Zimbabweans to the point of starvation and left 1,111 dead of cholera since August.

No apparent support for U.N. force
A day earlier at the United Nations, Secretary-General Ban Ki-moon said that during the past four months he has asked at least 50 nations and three international organizations to support the council's request for a multinational force to stabilize Somalia.