The White House on Tuesday said that President Barack Obama still backs John Allen, the US commander in Afghanistan, to take over as Supreme Allied Commander Europe -- the top military position in NATO.

White House spokesman Jay Carney said that though involved in " potentially inappropriate" correspondence with Tampa socialite Jill Kelley, Allen's star didn't dim with Obama.

The president "has faith in Gen. Allen," said Carney at a daily press briefing, adding that Obama still "thinks very highly of Gen. Allen."

Allen's correspondence with Kelley surfaced after the FBI began to investigate the extramarital affair between David Petraeus, the former CIA director, and his biographer Paula Broadwell. Allen has maintained that he did nothing wrong.

The National Security Council has said Allen's nomination to the NATO position has been put on hold, and he would not attend a confirmation hearing at the Senate Armed Services Committee scheduled for Thursday.