The reason for the move is because of the uncertainty over air travel between the UK and US due to the Icelandic volcanic eruption (as can be seen below), which has been wreaking havoc across Europe since Thursday and making the skies over Britain a no-fly zone meaning that the cast could not be brought into the country and the premiere would have lacked the usual red carpet glamour.
Stars including Robert Downey Jr, Mickey Rourke, Gwyneth Paltrow and Scarlett Johansson were all due to attend the event on 26 April.
A statement from Paramount Pictures said, "Due to the continuing air travel uncertainty, Paramount Pictures and Marvel Entertainment have taken the decision to move the Iron Man 2 world premiere and junket to Los Angeles. Advanced discussions are in progress about a special screening at the Vue Westfield, the original venue for the world premiere on April 26."
It is not known whether the star's scheduled appearance on this week's Jonathan Ross show will be affected by the decision to move the film's premiere.