At a White House ceremony, President Barack Obama has praised the outgoing Secretary of Defense as "exemplary," thanking him for the job he has done.
"When I asked Chuck to serve as the Secretary of Defense, we were entering a significant period of transition. The drawdown in Afghanistan, the need to prepare our forces for future missions, and tough fiscal choices to keep our military strong and ready."
In making the announcement, the President has revealed the two agreed at the end of last month that Hagel would leave his position.
Hagel, a former Republican Senator, says he plans to remain in the post until a replacement can be confirmed.
"As I said, and as the President
