One Direction member Harry Styles will be making his big screen debut in "Dunkirk," an upcoming English-language war film written and directed by Christopher Nolan.

While Styles may seem like an odd casting choice to some, Nolan maintained he was actually the perfect person for the role. He also admitted he was not fully aware of how famous the singer and songwriter was before casting him.

"I don't think I was that aware really of how famous Harry was," the 46-year-old English-American film director said in an interview with Billboard, adding, "I mean, my daughter had talked about him. My kids talked about him, but I wasn't really that aware of it."

Nolan went ahead to say that Styles auditioned for the role like everyone else and there no special treatment came into play. The director said he cast the 23-year-old musician because he fit the part superbly and truly earned a seat at the table.

In "Dunkirk," Styles plays a British soldier named Alex. He is one of thousands of Allied soldiers from Britain, Belgium, Canada and France who attempt to escape across the English Channel.

In a past interview, Styles described his first days on set as overwhelming. He said that "Dunkirk" is one of the most ambitious films ever produced; employing more than 6,000 extras and even assembled boats that had taken part in the real Dunkirk evacuation.

"I'd say realizing the scale of the production was very overwhelming," Styles said, adding, "I think whatever you imagine kind of a giant film set to be like, this was very ambitious even by those standards. You know the boats and the planes and the volume of bodies ... it was pretty amazing."

Also starring Tom Glynn-Carney, Fionn Whitehead, Tom Hardy, Jack Lowden, Mark Rylance, James D'Arcy, Kenneth Branagh, Cillian Murphy, Barry Keoghan and Aneurin Barnard, "Dunkirk" opens in North American theaters on Friday, July 21.