President Donald Trump's nominee to lead the Federal Bureau of Investigation pledged Wednesday to insulate the agency from outside interference, amid a probe into Russian election interference that threatens top White House officials.

"If I am given the honor of leading this agency, I will never allow the FBI's work to be driven by anything other than the facts, the law, and the impartial pursuit of justice. Period," Christopher Wray told a Senate Judiciary Committee hearing on his nomination.

"I consider the director's most important duty to ensure that nothing distracts the selfless patriots at the FBI from their mission."