Josh Hartnett thinks Christopher Nolan is a "genius" filmmaker.

The 44-year-old actor has relished the experience of working with the acclaimed director on his new biographical thriller movie 'Oppenheimer', having previously rejected the chance to work with him on the Batman franchise.

Josh - who stars in the film alongside Cillian Murphy, Emily Blunt and Matt Damon - told The Independent: "The thing about genius filmmakers is that they’re always gonna be around, so I hoped at one point that we’d work together. And, look, here we are.

"I feel really lucky that he still saw me as somebody he wanted to work with all these years later. I’m a big believer in things working out when they’re supposed to."

Josh has also been impressed by how Christopher approaches his work.

He shared: "Chris has certain rules: no one’s allowed a cell phone. No one comes in late. No one has an assistant. Everyone’s there as equals."

By contrast, Josh previously rejected the chance to play Batman in Christopher's most famous film franchise.

The actor explained that he wanted his career to go in a different direction at the time.

Josh - whose film credits include 'Pearl Harbor' and 'Black Hawk Down' - said: "So here’s what happened. Warner Bros wanted me to do one of their superhero films.

"Chris Nolan was directing one of their superhero films. I met him. I talked to him about it. It wasn’t something that was interesting to me at the time. I was on a different path to a lot of actors."