KIGALI — The United States is working to transfer Bosco Ntaganda, a Congolese warlord charged with war crimes, to the International Criminal Court "as quickly as possible" from the U.S. Embassy in the Rwandan capital, a senior U.S. official said on Wednesday.
 

Ntaganda surprised U.S. embassy staff in Kigali when he gave himself up on Monday after a 15-year long career that saw him fight as a rebel and government soldier on both sides of the Rwanda-Congo border.
 

He asked to be transferred to the International Criminal Court (ICC) where he faces war crimes charges.
 

"We believe that it is important to accommodate Bosco Ntaganda's request to be transferred to the ICC in The Hague," Johnnie Carson, U.S. assistant secretary of state for African affairs, told a conference call.
 

Washington broadly supports the Hague-based court but, like Rwanda, has not signed the Rome Statute that set it up.
 

"We are asking for the full and complete cooperation of the Rwandan government, the ICC authorities and the Dutch government to make this happen as quickly as possible," Carson said, speaking from Washington. He did not give a precise timeline.
 

Testimony by Ntaganda, who has fought in a string of Rwanda-backed rebellions in Congo's east, may be damaging for the government of Rwandan President Paul Kagame, a close U.S. ally.
 

His whereabouts had been unknown after hundreds of his fighters fled into Rwanda or surrendered to U.N. peacekeepers at the weekend following their defeat by a rival faction of M23 rebels in the mineral-rich eastern Congo.
 

Rwandan-born Ntaganda faces charges of recruiting child soldiers, murder, ethnic persecution, sexual slavery and rape during the 2002-3 conflict in northeastern Congo's gold-mining Ituri district.