Obama’s top adviser quits amid Guantanamo controversy

US President Barack Obama's top lawyer has resigned, amid an unsuccessful struggle to close the Guantanamo Bay prison.

Greg Craig a veteran Washington hand, who led the embattled effort to shutter the controversial camp for terror suspects in Cuba, said in a letter to Obama that he would step down as White House counsel on January 3.

AFP reported Obama saying: "Greg Craig is a close friend and trusted adviser who tackled many tough challenges as White House counsel," as he announced in a statement that his personal attorney, Bob Bauer, would take over the key post.

Obama praised Craig's role in winning Senate confirmation of Sonia Sotomayor as the first Latina US Supreme Court Justice and in overhauling controversial anti-terrorism strategies left over from George W. Bush's administration.

Craig, whose resignation letter was released by the White House, made no mention of the administration's struggles to meet Obama's self-imposed timeframe for closing the Guantanamo Bay prison by January 22.