The Expendables star Terry Crews has taken aim at U.S. leader Barack Obama, insisting the senator he met on his way to becoming the 44th President is still too "nice" to make a difference in America.

The former American football star-turned-action man and Tv personality admits he has always been a fan of Obama's, but he insists the man in the White House needs to develop a mean streak to beat off those opposed to his policies and projects.

Crews tells Wenn, "I met President Obama while he was running years ago... We went to a Democratic function and they stood me up in front of everybody. He just put his hands on my shoulders and said, 'Hi, I'm Barack Obama'.

"I thought he was the nicest guy, but in my mind I was like, 'He'll never be the President! He's too nice to be the President!' I really thought, 'Nice guy... they're gonna eat you alive! Well, you just keep going for your dreams, big guy!'

"Now deep into his second term, I still have to say, 'You're too nice. You're not mean enough'.

"I thought, to be a president, you have to be hostile and mean. He became an example for me because people have said the meanest things to him; so disrespectful and he never lets it get to him. That is the beautiful way to be. Always stand above the trolls, above the people trying to pull you down."

Watching diplomatic Obama in action has also made Crews realise he would be a terrible politician: "I know I would lose it (his temper); things that have been said to him... But he's so skilled at being so diplomatic and cool, because Barack Obama cannot have a bad day."