Less than a day after he announced that Marvel Studios was working on "Iron Man 4," Robert Downey Jr. backpedaled on his comments, though he doubled-down on his hopes to continue to work with Marvel beyond "Avengers: Age of Ultron."

Appearing last night on "Late Show with David Letterman," the man who brings Tony Stark to life retracted the statement he made earlier in the day on "The Ellen DeGeneres Show."

"There's no plans for an 'Iron Man 4.' There's no script for 'Iron Man 4,'" Downey stated. "But [Marvel does] have a plan and I think they're gonna announce it. You know, [Marvel's] very secretive about it."

Pressed by Letterman, Downey indicated that at the least, he and Marvel are having discussions about him continuing to portray Tony Stark. "I'm gonna do other stuff with Marvel. I'm still going to be involved with Marvel, and there's gonna be plenty of fun stuff to happen."

"Age of Ultron" was the next-to-last film on Downey's contract, so any future appearances in the Marvel Cinematic Universe beyond his final contracted movie would require a new deal. While speculation tends to center around the actor appearing in future big screen ventures, he indicated yesterday, in a Reddit AMA, that he is actively interested in making an appearance on ABC's "Agents of S.H.I.E.L.D."

UPDATE: An earlier version of this story stated that "Avengers: Age of Ultron" was the final film on Downey's contract. He has one more movie left in his current deal after "Avengers 2."