WASHINGTON (AP) — President Barack Obama has chosen longtime trusted adviser and national security expert Denis McDonough as his fifth chief of staff.

A White House official said Obama will announce McDonough's appointment Friday in the East Room. McDonough, 43, will take over the key West Wing role from Jack Lew, Obama's nominee for Treasury secretary.

McDonough has advised Obama on foreign policy for nearly a decade and most recently served as the president's deputy national security adviser. He is highly regarded by White House staffers.