Central Intelligence Agency (CIA) director Leon Panetta will take over at the Pentagon, and General David Petraeus will be nominated to head the CIA, officials confirmed on Wednesday.
Petraeus, who took over last June as the top U.S. commander in Afghanistan, was expected to leave that post before the end of this year, and Defense Secretary Robert Gates has made it clear he planned to leave his post this year.
President Barack Obama was expected to also announce that Lieutentant General John Allen would replace Petraeus as Afghanistan commander, and that veteran diplomat Ryan Crocker, the former U.S. ambassador to Iraq, will be the next U.S. ambassador in Afghanistan.
The changes were expected to be announced on Thursday at the White House and go into effect in the summer.
Officials confirmed the changes on condition of anonymity because the announcements had not been formally made.