In a new interview, the 76-year-old leading man discussed [warning: spoilers ahead] how little Anna Paquin speaks in the film, which explores hitman Frank Sheeran's claims surrounding the part he supposedly played in union leader Jimmy Hoffa's (Al Pacino) disappearance in 1975.
In the film, Paquin plays Peggy, De Niro's character's daughter, who, at a young age, fears her father. That fear turns into hate as she reaches adulthood and their characters rarely speak to each other, except for a few key scenes. Her quiet presence in the film has garnered its fair share of detractors from users on social media, who argue her silence renders her weak or ineffectual -- claims De Niro took issue with.
"She was very powerful and that's what it was," he tells USA Today. "Maybe in other scenes there could've been some interaction between Frank and her possibly, but that's how it was done. She's terrific and it resonates."
Near the film's end, after Hoffa has vanished. Frank is shown with his family watching the news of his boss' disappearance. He admits that he hasn't called Jo, Hoffa's wife, yet. It's at this point that Peggy pointedly asks him why he hasn't called her. They are the actress' only lines in the film, amounting to just seven words. It's also one of the few times Frank's violent, secretive lifestyle is questioned by his family.
In October, De Niro chatted with ET at the film's L.A. premiere, where he discussed the involved process of de-aging him for certain portions of the film, which spans four decades of his character's life.
"It was OK. I just wanted it to work as best as it can," he said when asked how he felt seeing himself looking younger. "And they did a very good job, I felt. They tried to make it the best to date that it could be."
The actor also discussed the years it took him and director Martin Scorsese to get the epic gangster film made, stating: "We worked on it for a long time, so finally we were able to do it and complete it and get it out. So, we're very happy that we were able to do it." The film went into development in 2007.
The Irishman is now available to stream on Netflix.
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