The actor recently reprised his role as Tony Stark in Iron Man 2, starring opposite Gwyneth Paltrow, Mickey Rourke and Scarlett Johansson.
Despite the sequel only being released this week, Downey Jr confirmed that plans are already afoot for the character to return in a solo outing after The Avengers, which will see Iron Man team up with The Hulk, Thor and Captain America on the big screen.
He told MTV news: "I think it's [Iron Man 3] going to go down. [The Avengers is] supposedly first on [Marvel Entertainment's] docket. I have some pretty strong ideas, but they never seem to be too discordant with what the creative execs at Marvel are thinking anyway.
"It's all there. There's a little bit of a bunch of different storylines from different decades [in the comics]."
> Video: Four new clips from 'Iron Man 2'