Charlie Hunnam and Robert Pattinson didn't exactly form a bromance on the set of The Lost City of Z.
The 36-year-old actor opened up about working with Pattinson on the upcoming film, which is centered around British explorer Percy Fawcett, who disappeared in 1925 while on a search for a mythical city that he believed existed in the Amazon.
EXCLUSIVE: Charlie Hunnam Bummed He Never Got His Promised 'King Arthur’ Sword, Cops to Stealing a Bike From 'Sons of Anarchy'
Hunnam portrays Percy in the biographical drama, while Pattison plays fellow explorer Henry Costing. The cast also includes Sienna Miller as Percy's wife, Nina Fawcett, and Tom Holland as the couple's son, Jack Fawcett.
"I had a couple of rehearsal sessions with Sienna, but I didn’t spend any time with Tom [Holland] or Robert," the Sons of Anarchy star told Screen Daily in an interview published on Saturday. "I wanted these relationships to evolve naturally on screen."
As for Pattinson, Hunnam admitted that they didn't speak very much when the cameras weren’t rolling.
"I don't think I said more than 10 words to Robert off camera," he confessed. "I didn't know if he was just 'in that zone' or if he genuinely didn't like me. There was a real distance between us. But it creates the right dynamic on screen. He's reached out to me subsequently, making overtures for us to be friends now, so I think it was about the work."
WATCH: Shirtless Charlie Hunnam Heats Up the 'King Arthur: Legend of the Sword' Trailer -- See the Clip!
Despite the seemingly awkward run-ins with Pattinson, Hunnam gushed about the film's writer and director, James Gray.
"James is my kind of director," Hunnam said, revealing that the he had lots of "one-on-one" conversations with Gray in place of formal rehearsals. "His understanding of narrative and the filmmaking process is so absolute. I felt free to take risks."
"Some filmmakers start to make too many choices and the essence of your performance can be lost," Hunnam added. "But with James, I just knew he got it."
The Lost City of Z hits theaters in New York and Los Angeles on April 14, before going wide on April 21.
MORE: Charlie Hunnam Explains Why He Has Not Seen 'Fifty Shades of Grey' Since Backing Out of Movie