The One Direction star has begun filming his first ever movie role in Christopher Nolan's upcoming World War II drama about the evacuation of Allied troops from French beaches in 1940, and his bandmate Niall has every confidence he will impress audiences with his acting skills.

"I actually met this guy on the Tube the other day who’s doing special effects on the movie and he told me that, yeah, apparently Harry is a good actor," Niall tells Britain's The Sun newspaper. "I'll tell you what - if Christopher Nolan takes you on you must be a good actor.

"I'm looking forward to seeing it - it's going to be an unbelievable movie but when one of your mates is in it then it's going to be even better... I think he is going to do well."

Harry had to chop off his signature long locks to play a soldier in the movie, which also stars Tom Hardy and Kenneth Branagh, and Niall reckons the 22-year-old would have been nervous to lose so much hair because he spent two years growing it out. He adds, "I wouldn't say he was too happy about it but it is what it is, he's in a movie now."

Niall, 22, is confident that he won't follow in the footsteps of Harry and Louis Tomlinson, who is rumoured to be playing British soccer star Jamie Vardy in a biopic, because he doesn't have the patience for acting.

Dunkirk casting director John Papsidera recently defended his decision to give Harry a role, insisting his casting was down to his acting ability, not star status.

“Harry was absolutely right for the role," he previously told Britain's The Mirror newspaper. “It wasn’t because he’s a well known pop star – if anything that was more of a detriment, because it could bring the wrong message and we don’t want people pulled out of the film because of who they are.

“So Harry really had to overcome hurdles to get past that. He fought hard for it and his work was impressive and that’s what attracted us to him."