U.S. President Barack Obama is turning to a long-time aide to fill one of the most influential positions in Washington.
Mr. Obama Friday named key adviser Denis McDonough as his fifth chief of staff.
McDonough previously served as a White House foreign policy advisor. He was one of the aides photographed with Mr. Obama as he watched the U.S. special forces raid that killed al-Qaida leader Osama bin Laden in May 2011.
Mr. Obama called McDonough indispensable, saying he is "a great friend to me and everybody who works here at the White House."
McDonough takes over for Jack Lew, who has been nominated to take over as secretary of the Treasury.
The White House also announced several other staff changes Friday.
Separately, a federal appeals court ruled Friday that three of the president's appointment to a labor relations board were unconstitutional.
Mr. Obama made the appointments to the National Labor relations Board last January while the Senate was not in session.
In the past, U.S. presidents have used so-called "recess appointments" to bypass the Senate, which sometimes will try to block a president's nominees.
In this case, the appeals court ruled the recess appointments were not valid because, although the Senate was not meeting, lawmakers were still available to act on the nominations.