Christopher Nolan's "secretive" movie set ensured Harry Styles' fame didn't intrude on 'Dunkirk'.

The 46-year-old director - who's helmed the much-anticipated new drama film - revealed Harry was cut off from the world during his time on set and was instead busily trying to learn as much as he could from the film's star-studded cast, which also includes Tom Hardy, Mark Rylance and Sir Kenneth Branagh.

Christopher shared: "We always have a secretive set anyways. So we're sort of used to shutting things off and really trying to create our own world. So, none of that really intruded on our creative process, which was terrific.

"Harry was very committed and determined to just being one of the guys and coming there and learning what he could from the most experienced people around him and diving into the role feet first.

"I think he's done an incredible job on the film and I'm really excited to show it to people."

Meanwhile, Harry is proud to have appeared alongside so many talented people in the new movie, which is based around the Dunkirk evacuation during World War Two.

The 23-year-old star told 'Entertainment Tonight': "The film is so amazing and I think it tells such an important story.

"I think [it had] such an amazing list of actors working on it and I feel like we were all working towards the same thing."

And Harry admitted to feeling fortunate at having been offered the chance to help tell such an extraordinary story.

He said: "I don't feel like [filming] really allowed any time to think too much about specifically what I was doing or anything.

"I think the movie is amazing and I just feel very lucky to kind of be a part of it, really."