CIA director Leon Panetta will be nominated to take over as U.S. defense secretary when Robert Gates retires in 2011, according to reports.
Gen. David Petraeus, the head of international forces in Afghanistan, meanwhile will be nominated as CIA director when Panetta moves to head the Pentagon, according to sources quoted by several news outlets.
The changes, which would require confirmation in the U.S. Senate, were to be announced on Thursday, the AP's sources said.
The shuffling of the top national security jobs would end weeks of speculation.
President Barack Obama was expected to nominate veteran diplomat Ryan Crocker as the next U.S. ambassador to Afghanistan. Crocker would succeed Karl W. Eikenberry, a retired Army lieutenant general who has had cool relations with some in the White House as well as Afghan president Hamid Karzai.
The departure of Gates, appointed as defense secretary by George W. Bush in 2006, had long been expected to come this year. Joint Chiefs Chairman Mike Mullen also planned to leave his post this fall, according to Politico.