"Iron Man" Robert Downey Jr.Getty Images

The 'Avengers: Age of Ultron' star, who plays Iron Man in the franchise, created a frenzy at the movie's European premiere at the Vue Cinemas in the Westfield, London, but thinks it's time he "passed the torch" on to his younger co-stars.

Asked about the adulation, the 50-year-old star joked to BANG Showbiz: "It's really good for my ego because I'm so introverted.

"But look, all that matters is that I think we made a better movie this time. I didn't know that we could do that, but the fans won't be disappointed.

"It's about time I passed the torch [to other Avengers] - it's been getting hot in my hands."

The blockbuster is a follow-up to 2012's hit 'Avengers Assemble' - both of which were directed by Joss Whedon - and Robert admits they "put a lot of pressure" on themselves to improve on the first film.

He said: "We put a lot of pressure on ourselves to try to make a movie that was as good or better than the first one, and I think it's better than the first one."

Other stars at the premiere included Scarlett Johansson, Chris Hemsworth, Jeremy Renner, Elizabeth Olsen, Mark Ruffalo, Paul Bettany and Chris Evans.