'Oppenheimer,' starring Matt Damon, Emily Blunt and others, hits theaters July 21
Christopher Nolan and Cillian Murphy joined forces on the highly anticipated war film "Oppenheimer," and Murphy admitted he felt "pressure" collaborating with the famed British-American director.
Although the two have worked together in Hollywood for more than 20 years, Murphy, 47, said he "for sure" felt an overwhelming responsibility to perform his best in Nolan’s latest film.
"Pressure is good because it pushes you... pushes you to your limits," Murphy told Fox News Digital.
Cillian Murphy, right, told Fox News Digital he felt the pressure of being the male lead in Christopher Nolan's highly anticipated war film "Oppenheimer." (Getty Images)
"He certainly does that with me. Always pushes me."
The film is based on the Pulitzer Prize-winning book, "American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer," by Kai Bird and the late Martin J. Sherwin.
Murphy plays the male lead in the explosive film, physicist J. Robert Oppenheimer, the "father of the atomic bomb."
WATCH: 'OPPENHEIMER’ STAR CILLIAN MURPHY REVEALS WHAT IT'S LIKE WORKING WITH MATT DAMON, EMILY BLUNT
He stars alongside Oscar-winner Matt Damon, who plays Gen. Leslie Groves Jr., director of the Manhattan Project -- a top-secret program led by Murphy’s character that designed and developed the first atomic bomb during World War II.
Emily Blunt plays Murphy's his wife, Katherine "Kitty" Oppenheimer, who is a biologist and botanist. Academy Award nominee Florence Pugh and Robert Downey Jr. also star in the film.
From left to right, Robert Downey Jr, Emily Blunt, Cillian Murphy, Florence Pugh and Matt Damon attend the photocall for "Oppenheimer" in Trafalgar Square on July 12, 2023 in London. (Getty Images)
Murphy told Fox News Digital it was "amazing" working with such a star-studded cast.
"They're such brilliant, brilliant actors. There's a reason why they are movie stars, and they're… just also great people," he said.
"I'd worked with Emily before on ‘Quiet Place 2’… we were very close. And I think that was smart casting by Chris to put us as husband and wife."
WATCH: ‘OPPENHEIMER’ STARS MATT DAMON, EMILY BLUNT ‘LOVE LIVING IN THE SAME BUILDING’
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The "Peaky Blinders" star added that he "really admired" Pugh and enjoyed working with her on the "Oppenheimer" set.
"Every day was a buzz," Murphy remarked.
Cillian Murphy also starred in "Dunkirk," directed by Christopher Nolan. Pictured is the cast at the London world premiere. From left to right, Barry Keoghan, Aneurin Barnard, Jake Lowden, James D'arcy, Sir Mark Rylance, Cillian Murphy, Fionn Whitehead, Harry Styles, Emma Thomas, Christopher Nolan, Tom Hardy and Sir Kenneth Branagh. (Getty Images)
Meanwhile, Murphy and Nolan’s work relationship spans over two decades, as the filmmaker has directed the actor in popular movies including "Inception," "Dunkirk" and the "Batman" franchises.
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Nolan is known for directing several award-winning films and explained whether he thinks "Oppenheimer" will top his previous movies.
WATCH: ‘OPPENHEIMER’ DIRECTOR CHRISTOPHER NOLAN ON WHETHER HE THINKS WAR FILM WILL TOP HIS OTHER MOVIES
"I don't know if it's a case of topping it so much as just looking at each story on its own merits," Nolan told Fox News Digital.
"The thing about ‘Oppenheimer’ is I know of no story as dramatic as the real-life tale of Oppenheimer. His involvement with the Manhattan Project… in this crazy, desperate race against the Nazis to harness the power of the atom for the first time."
"Where that led and how that defined the world we live in. His story is just full of paradox and intrigue… it's just one of… the great stories."
"Oppenheimer" is in theaters July 21.
Stephanie Giang-Paunon is an Entertainment Writer for Fox News Digital. Story tips can be sent to
