The U.S. State Department on Monday said it supports the decision of Somalia's politically-embattled President Abdullahi Yusuf to resign as head of the country's transitional government.  The United States will contribute $5 million to the formation of a joint security force of Somali factions. 

Officials here are welcoming the resignation of President Yusuf and expressing hope that the move will help clear the way for a unity government that can prevent a slide into chaos when Ethiopian peacekeeping troops withdraw.

The president had been facing pressure to step down after losing a power struggle with Prime Minister Nur Hassan Hussein, who has been pushing a reconciliation plan that would bring a moderate Islamist opposition faction into the government.

Here in Washington, State Department Acting Spokesman Gordon Duguid said the United States supports and respects Mr. Yusuf's decision to step aside and acknowledges what he termed the Somali leader's contributions to long-term peace and stability in his troubled country.

Duguid said Somalia's parliament should act quickly to select a new president within 30 days - under the terms of the transitional federal charter - and that other key figures in the government should work for unity and stability.

"We urge the parliament, the prime minister and leaders of the Alliance for the Re-liberation of Somalia to intensify their efforts to achieve a government of national unity and to enhance security through the formation of a joint security force," said Gordon Duguid. "To that end, the United States is ready to provide $5 million to support the formation of such a joint security force."

The spokesman reiterated U.S. support for strengthening the African Union Mission in Somalia - AMISOM - and for the rapid authorization and deployment of a United Nations peacekeeping force.

President Yusuf's resignation comes days before Ethiopia's expected withdrawal of the troops it sent to Somalia two years ago to support the United Nations-backed transitional government.

The Ethiopian pullout will leave only the 3,400 member African Union peacekeeping force in place, raising fears that the weakened transitional government might collapse and be replaced by Islamic extremists.

A senior U.S. official says the Bush administration has not given up hope that the AU force can be expanded and a U.N. force eventually deployed, and said the proposed joint security force of Somali factions would help prevent a near term security vacuum that Islamist and clan elements could exploit.

Security concerns have mounted as the Ethiopian pullout nears.  Insurgents already control parts of the capital, Mogadishu, and are poised to take over remaining areas after the Ethiopians depart.

Countries from several major powers, including the United States, China and France, are patrolling Somali coastal waters to deter pirates.  But the United Nations has been unable to find countries willing to participate in a land peacekeeping mission, although one was authorized more than two years ago.