Robert Downey Jr. has discussed the possibility of returning to his infamous armour for a fourth installment in the Iron Man franchise, admitting he's pretty torn about it.

Speaking to Entertainment Weekly, Downey Jr. seemed to suggest that nothing's set in stone, despite previous claims that he may be getting to old for the gig.

“It’s down to Kevin [Feige, Marvel Studios president] and Ike [Perlmutter, CEO of Marvel Entertainment] and Disney to come to us with what the proposal is, and that’s on us to agree or disagree,” Downey said. “When things are going great, there’s a lot of agreement.

"Right now, this has just been swell, hasn’t it?” he continued, in reference to the upcoming Avengers: The age of Ultron. “This has been a really good one and it feels good and we’re having a good time.

“It’s that thing of: Why give up the belt when it feels like you can barely get jabbed?” he apparently said, before adding, “Most people are saying that right when they get knocked out. The future is, as usual, uncertain."

There's been a wealth of discussion and casting woes around the future of The Avengers for some time, with Downey Jr., Chris Hemsworth and Scarlett Johansson all reportedly arguing with Marvel over fees for the second movie at various times in production.

Seeing as the Iron Man actor is officially the highest-paid actor in Hollywood, if Disney and Marvel do want to lure him back for another stand-alone film, you can bet it's going to cost them.