Robert De Niro says audiences will understand 'Joker' once they've watched the movie.

The 76-year-old actor - who plays late night talk show host Murray Franklin in the upcoming comic book thriller - has opened up on the controversy surrounding the movie, with some critics claiming it could encourage violence.

Speaking to Variety, De Niro said: ''I like Todd Phillips and Joaquin [Phoenix]. They were terrific to work with and, you know, I'm a small part of it and they kind of - the association of me with 'Taxi Driver' and 'King of Comedy' is part of it, though it's different, you'll see.

''When you see the movie you'll get why. So that's it. We'll see what happens. I know there's controversy.

''I think some of the things that were being said about Warner Bros. giving money, not endorsing - or whatever it was about the NRA - I think is right.''

His comments come after families of victims killed in the 2012 movie theater mass shooting in Aurora - which occurred during a screening of 'The Dark Knight Rises' - wrote to 'Joker' studio Warner Bros. to call for donations to gun victim charities.

They claimed the film - directed by Phillips and starring Phoenix in the title role - ''presents the character as a protagonist with a sympathetic origin story''.

In response, the company said: ''Gun violence in our society is a critical issue, and we extend our deepest sympathy to all victims and families impacted by these tragedies.

''Our company has a long history of donating to victims of violence, including Aurora, and in recent weeks, our parent company joined other business leaders to call on policymakers to enact bi-partisan legislation to address this epidemic.

''At the same time, Warner Bros. believes that one of the functions of storytelling is to provoke difficult conversations around complex issues.

''Make no mistake: neither the fictional character Joker, nor the film, is an endorsement of real world violence of any kind. It is not the intention of the film, the filmmakers or the studio to hold this character up as a hero.''