(This post was last updated at 11:41 a.m. ET.)
Secretary of Defense Chuck Hagel, the highest-profile Republican on President Obama's Cabinet, will step down, once his successor is confirmed by the Senate.
Calling Hagel an "exemplary defense secretary," Obama made the announcement in the State Dining Room of the White House on Monday.
Hagel, a two-term Republican senator, came to the post in February of 2013, the first enlisted combat veteran to lead the Department of Defense.