In a new interview, Avengers: Age of Ultron star Robert Downey Jr. revealed that he would be interested in reprising his role as billionaire Tonk Stark's heroic alter ego in the potential Iron Man 4 movie.

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

The 49-year-old New York City native also talked about the success of the Marvel films he starred in since 2008 when the first Iron Man debuted in theaters that year.

"Right now, this has just been swell, hasn't it?" said Downey Jr., "This has been a really good one and it feels good and we're having a good time."

The actor talked why he wants to return to popular film franchise that made him highest-paid actor in America, with a projected $75 million in the last year, according to Forbes magazine.

"It's that thing of: Why give up the belt when it feels like you can barely get jabbed?" said Downey Jr., "Most people are saying that right when they get knocked out... The future is, as usual, uncertain."

Marvel Studios President Kevin Feige also discussed the possibility of Downey Jr. reprising his role in the upcoming film.

"Anything's a possibility. Who the heck knows? We have a lot of work to go to finish 'Avengers 2.' We have a lot of work for whatever 'Avengers 3' is, that's all folks need to know. Who knows what happens after that," said Feige to Collider.

The Avengers: Age of Ultron movie is expected to arrive in US theaters on May 1, 2015.