Todd Phillips has ruled out a movie starring Joaquin Phoenix's Joker and Robert Pattinson's Batman.

The pair take on the roles of the super-villain and Caped Crusader in 'Joker' and 'The Batman' respectively, but the helmer of the former film gave a resounding ''no'' when asked if he sees the two characters coming together.

He told Variety: ''No, definitely not.

''Oddly, in the states, comic books are our Shakespeare it seems, and you can do many many versions of 'Hamlet'.

''There will be many more jokers, I'm sure, in the future.''

Meanwhile, Phillips recently revealed he was drawn to the role because he didn't feel like the Clown Prince of Crime's origin had really been touched on before.

He said: ''I love the complexity of Joker and felt his origin would be worth exploring on film, since nobody's done that and even in the canon he has no formalised beginning.

''So, [co-writer] Scott Silver and I wrote a version of a complex and complicated character, and how he might evolve ... and then devolve.

''That is what interested me - not a Joker story, but the story of becoming Joker.''

The filmmaker added how ''empathy'' was a big theme in the movie, which follows Arthur's Fleck's journey from a failed stand-up comedian to villain.

He added: ''One of the themes we wanted to explore with the movie is empathy and, more importantly, the lack of empathy that is present in so much of Arthur's world.

''For example, in the movie you see the difference in the way little kids and adults react to Arthur, because kids see the world through no lens; they don't see rich versus poor or understand a marginalised individual the way adults do.

''They just see Arthur as a guy who's trying to make them smile.

''It's not inherent, we have to learn how to be unaccepting of others and, unfortunately, we usually do.''