The war epic Dunkirk focuses on the survival of British and French troops on the French beach in 1940. [Photo provided to China Daily]

Christopher Nolan's Dunkirk will make its debut on the Chinese mainland on Sept 1. Xu Fan reports.

Fans of Christopher Nolan gathered outside Beijing Wanda CBD Cinema in the rain this week for a sneak peek into his World War II epic Dunkirk.

The movie, which tells the story of the 1940 evacuation of Allied soldiers from the beaches of Dunkirk, France, will open across the Chinese mainland on Sept 1.

Nolan, who's known in China for Interstellar, attended a promotional screening of Dunkirk on Tuesday alongside his wife, who's the movie's producer, Emma Thomas.

The film weaves three separate plots over land, sea and sky. It focuses on the survival of British and French troops.

"What is interesting to me about the Dunkirk story is the simple, clear and paradoxical situation. We had 400,000 men on the beaches－so close to home but unable to get there," Nolan said in an interview on Monday during his first visit to Beijing.

"We try to use the points of view from people who were actually there. We try to be true to what might be the experiences of those people."

The 47-year-old British-American filmmaker had the idea for a long time.

When Nolan was producing his first movie, Following, in the late 1990s, he and Thomas used a small ship to sail across the English Channel. The 19-hour journey also retraced the route that around 850 private boats sailing from England to Dunkirk took to help rescue thousands of soldiers trapped on the French beach.

"We were very struck by the experience. It was incredibly dangerous. The water was turbulent. It took a much longer time than we'd thought, because the conditions were poor," Nolan recalled at another promotional event in Beijing on Tuesday.