President Donald Trump provoked his own national anthem controversy on Monday night, first booed as he took the field before a big college American football game and then appearing to mumble and stumble his way through the words to the Star Spangled Banner.

Social media lit up with commentators wondering whether he had forgotten the words and reigniting speculation about his mental health.

Critics took glee in pointing out how Mr Trump had railed against football players failing to respect the national anthem.

He was appearing at the College Football Playoff National Championship Game between the Alabama Crimson Tide and the Georgia Bulldogs in Atlanta.

There was further controversy when an Alabama running back was picked up by microphones dismissing the American president with a shouted expletive.