WASHINGTON (Reuters) - President Barack Obama named longtime foreign policy aide Denis McDonough to be his next White House chief of staff on Friday.

Calling him a hard worker who liked pulling "all-nighters," Obama said McDonough had played a key role in every national security decision of his administration.

"Nobody outworks Denis McDonough," Obama said.

McDonough takes over for Jack Lew, whom Obama nominated to be his next Treasury secretary.

(Reporting by Jeff Mason and Mark Felsenthal; Editing by Vicki Allen)