Last year, Biden nominated Denver International Airport Chief Executive Officer Phil Washington to serve as FAA administrator.

The agency has faced questions in recent months after a series of close-call safety incidents and the Senate Commerce Committee earlier this week delayed a vote on his nomination citing outstanding questions by some lawmakers.

One of the sources, a White House official, told Reuters that "an onslaught of unfounded Republican attacks on Mr. Washington's service and experience irresponsibly delayed this process, threatened unnecessary procedural hurdles on the Senate floor, and ultimately have led him to withdraw his nomination today."

(Reporting by David Shepardson, editing by Deepa Babington)