Does Christian Bale put on his American accent all of the time, even in interviews? Im sure that he is Welsh and raised in England - but he never seems to sound English (apart from a tiny bit in his rant haha) - or has he just lost his accent now?
He uses whatever accent he has for a certain film for all promotional appearances related to that film. He hasn't done a film without an American accent since The Prestige, so he hasn't used his real accent in interviews since then.