Robert Downey Jr. is in talks to join the cast of “Captain America 3” as “Iron Man," media reports said Monday. The movie will reportedly be directed by Joe and Anthony Russo, the brothers who directed the popular “Captain America: The Winter Soldier.”

The storyline will revolve around Marvel's seven-part "Civil War" comic book series, which pits the two Avengers teammates against each other, Variety reported. Downey is reportedly set to play Iron Man in two movies next year -- “The Avengers: Age of Ultron” and “The Avengers 3.”

"There's no plans for an 'Iron Man 4,’” Downey reportedly told David Letterman during an interview on Oct. 7. "There’s no script for 'Iron Man 4,' but they do have a plan, and I think [Marvel is] going to announce it. You know, they're very secretive about it."

Marvel Entertainment on Monday posted a picture hinting at a Civil War comic book miniseries in 2015.

According to reports, Downey will play a major role in “Captain America 3,” which is due to release on May 6, 2016. Marvel wanted Downey to play a small role in the film, which would have required only three weeks of work, but Downey wanted the Stark character to have a more substantial role in the film’s plot, Variety reported.

Downey’s three “Iron Man” movies have reportedly earned $2.4 billion worldwide, while the first Avengers earned a record-breaking $1.5 billion worldwide in 2012.