Robert Downey Jr. Declares 'Oppenheimer' the 'Best Film I've Ever Been In'

"Just going to flat out say it," the Marvel star said before making the admission at the movie's London premiere

Marvel fans, cover your ears!

According to Robert Downey Jr., Oppenheimer is the best film he has acted in.

At the London premiere of the Christopher Nolan-directed historical drama on Thursday, the Iron Man star, 58, revealed that the movie is a career-best for him, according to a video shared by Deadline on Twitter.

Related: 'Oppenheimer' Cast Walked Out of U.K. Premiere Before SAG Strike: 'Off to Write Their Picket Signs'

“Just going to flat out say it: This is the best film I’ve ever been in,” he said in the video, a declaration that was met with cheers from the premiere audience at Odeon Luxe Leicester Square. “I cannot wait for you all to experience it.”

Downey — who portrays Lewis Strauss, primary antagonist of titular physicist J. Robert Oppenheimer (Cillian Murphy) — goes on to say that “no matter what your expectations are” going into the dark period piece, which follows the effort to create an atomic bomb during World War II, it “transcends that.”

Related: 'Oppenheimer': Meet the Star-Studded Cast of Christopher Nolan's Atomic Bomb Epic (Exclusive Photo)

"This is what a summer blockbuster, when I was growing up, used to be,” he continued. “It just kind of, like, changed your life. But again, you know, it’s why Chris Nolan is who he is.

Downey’s interview came just before he and his castmates walked out of the premiere in solidarity with the Hollywood actors' strike.

When he and his Oppenheimer costars including Murphy, Florence Pugh, Matt Damon, Rami Malek, Josh Hartnett and Emily Blunt left the theater after walking the red carpet, Nolan, 52, addressed their sudden absence in relation to SAG-AFTRA's then-looming strike against the Alliance of Motion Picture and Television Producers (AMPTP).

Related: Robert Downey Jr. Reflects on Badly-Reviewed ‘Dolittle’ Movie: ‘I Had Some Reservations’

"We have to acknowledge, you've seen them here earlier on the red carpet,” the director said, as captured by another Deadline-shared video. “Unfortunately, they're off to write their picket signs for what we believe to be an imminent strike by SAG.”

He continued, "Joining one of my guilds, the Writers Guild, in the struggle for fair wages for working members of their union, and we support them.”

Before her departure, Blunt, 40, who plays Oppenheimer’s wife, Kitty, told Deadline, “If they call [a strike], we’ll be leaving together as a cast in unity with everyone. We're gonna have to."

Related: Robert Downey Jr. Hangs Out with 'Oppenheimer' Cast in N.Y.C. — Including a 'Photobomb' from John Krasinski

“But right now, it’s the joy to be together,” the A Quiet Place star added.

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In a new interview with The New York Times Magazine, Downey opened up about his journey as an actor post-Iron Man, which began with Dolittle — a film that flopped hard following its 2020 release.

“I finished the Marvel contract and then hastily went into what had all the promise of being another big, fun, well-executed potential franchise in Dolittle,” he told the magazine. “I had some reservations. Me and my team seemed a little too excited about the deal and not quite excited enough about the merits of the execution.”

Related: 'Oppenheimer' Cast Squeezes in London Premiere Red Carpet as Potential Actors Strike Looms

“But at that point I was bulletproof,” he explained. “I was the guru of all genre movies.”

Thankfully, Downey told the outlet, his post-Marvel career eventually led him to Oppenheimer. “Then old Chris Nolan calls, and getting to see the spartan, almost monastic way he approaches this art form, it was like going to the other side of the moon,” he said.

Oppenheimer premieres in U.S. theaters July 21.

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