WASHINGTON (Reuters) - President Barack Obama has faith in General John Allen to continue commanding U.S. forces in Afghanistan while under investigation for alleged inappropriate communication with a woman at the center of the scandal involving former CIA Director David Petraeus, the White House said on Tuesday.

"He has faith in General Allen," White House spokesman Jay Carney told reporters, saying the president believed Allen was doing a good job in Afghanistan.

Carney reiterated Obama's call for the Senate to move quickly to confirm Allen's successor, General Joseph Dunford.

(Reporting By Margaret Chadbourn)