'Iron Man 3' director Shane Black believes Robert Downey Jr. will return for the fourth movie.The 48-year-old actor has thus far refused to confirm if he will make another movie in the successful franchise but director Shane Black is confident Robert will return for at least one more outing as Tony Stark/Iron Man.Speaking at the 'Iron Man 3' UK premiere at Odeon Leicester Square in London on Thursday (18.04.13), Shane told BANG Showbiz: "I think he'll be back for another one. I'm sure of it."Co-star Sir Ben Kingsley heaped praise on Robert for his portrayal of the billionaire businessman turned superhero.He said: "I think what the film examines, thanks to Robert Downey Jr.'s wonderful sense of performance is, you have the iron suit and the man inside it. Which is which? Which is the more powerful? Is it the guy inside the suit, or is it the suit itself?"Meanwhile, Rebecca Hall, who plays Maya Hansen, couldn't hide her delight at joining the cast.She said: "I'm really excited to be here. I'm really excited to be part of it. It's definitely a unique experience to join a franchise when you know so much of it already and you're already acquainted with who the characters are and you've seen them in the cinema. It's an exciting thing to get on board that. It's very thrilling."Robert, also attended the premiere along with Don Cheadle while stars including Demot O'Leary, Oritse Williams and J.B. Gill from JLS, Labrinth and Kimberly Wyatt walked the red carpet.Photos in the gallery show snapshots of Robert Downey Jr. using shoe lifts to appear taller for Iron Man.