Washington, D.C. ? Sudan will have to accept non-African troops in a U.N.-authorized peacekeeping force for Darfur or face the prospect of new United Nations sanctions, a senior U.S. official said Tuesday.

Although efforts will be made to ensure that Africa contributes a large percentage of the 26,000-strong mission, the continent does not have enough trained soldiers to fully staff the force and Sudan will be penalized unless it drops objections to non-African participation, said Andrew Natsios, the U.S. special envoy for Sudan.

President Bush has made ending the Darfur conflict a U.S. foreign policy priority but the United States is reluctant to provide troops itself for the force, given military commitments in Iraq and Afghanistan. Instead, Washington is likely to contribute logistics and transportation to the mission.

Meanwhile, the State Department called Hollywood actress Mia Farrow naive for her offer to give up her freedom to guarantee safe passage of a Darfur rebel leader from a U.N hospital where he is being treated.