Christopher Nolan thinks 'Oppenheimer' can be considered a "horror movie".

The 52-year-old director has helmed the new blockbuster about J. Robert Oppenheimer, the creator of the atomic bomb, and feels that it is darker than his previous projects.

Speaking to Wired magazine, Christopher said: "It is an intense experience, because it's an intense story. I showed it to a filmmaker recently, who said it's kind of a horror movie. I don't disagree.

"It's interesting that you used the word nihilism earlier, because I don't think I'd quite managed to put my finger on it. But as I started to finish the film, I started to feel this colour that's not in my other films, just darkness. It's there. The film fights against that."

Christopher revealed that the film – which has an all-star cast featuring Cillian Murphy, Robert Downey Jr. and Florence Pugh – has had a profound impact on those who have watched early screenings.

The 'Inception' director said: "Some people leave the movie absolutely devastated. They can't speak. I mean, there's an element of fear that's there in the history and there in the underpinnings.

"But the love of the characters, the love of the relationships, is as strong as I've ever done."

Nolan confessed that he was "relieved" to have completed the movie as it had left him emotionally drained.

He explained: "I was relieved to be finished with it, actually.

"But I enjoy watching the film tremendously. I think you'll understand when you see the film. It's a complicated set of feelings to be entertained by awful things, you know? Which is where the horror dimension comes in."