Clint Eastwood has laughed off claims he threatened to kill Michael Moore and denied holding a grudge against the film-maker for criticising his movie American Sniper.

But Eastwood, 84, could not resist adding "It isn't a bad idea", at a tribute lunch for the actor and director at the CinemaCon convention in Las Vegas.

Eastwood, who directed American Sniper, was responding to comments from the outspoken Moore on social media and in interviews criticising the film - and a reported confrontation between the two in 2005.

"I said, 'Hey, he's probably right'," Eastwood told cinema owners at the annual conference. "He was just expressing an opinion."

He discussed subjects as varied as the film that made the most impact on him as a child -Sergeant York - his early struggles in the business, and the highs and lows of directing.

Eastwood said projects consumed his life and thoughts completely and when they were over "there's sort of a post-partum thing that comes over you".

But it was the box office success of American Sniper that most interested the audience. Eastwood attributed the appeal of the film to the fact that Afghanistan and Iraq are on people's minds.

"Everyone has opinions on it, but nobody's really thought about it from the point of view of the families of the people over there and the people who go over there ... and donate their time for a belief that some of us think is a great idea and some of us don't think is a great idea," he said.

"It opens a lot of questions that are fun to broach."

Eastwood said he "ain't stopping" when it comes to making movies, but there is one genre he probably will not dabble in: superhero films.

"I read comic books when I was a kid," he said. "I don't read them now."