Williams has also entertained in Afghanistan

Following in the footsteps of Bob Hope and Bruce Willis, the actor entertained soldiers on Tuesday on an outdoor stage at Baghdad International Airport.

The Good Will Hunting star opened his act with "Good Morning Baghdad" - a reprise of his signature line from the 1987 film Good Morning Vietnam.

He was joined on stage by ex-Playboy model Shannon Tweed, stock-car racer Mike Wallace and wrestler Kurt Angle.

The show was the first in a tour of US bases in Iraq.

Wearing a camouflage outfit, Williams entertained the crowd of 200 American and Australian soldiers.

"I'm looking at a group of heavily armed people here," Williams joked with the soldiers. "I'm telling myself, 'If you're not funny, it's a problem'."

He has previously visited Afghanistan, where he met the troops, signed autographs and posed for photographs.