No! That's not how Hollywood works. Welsh (or Irish / Scots /English) actors are allowed to play Americans as lead roles in US backed films. Hopkins (and Brian Cox) as Lecter, Bob Hoskins in Roger Rabbit, Colin Farrel in Miami Vice. But if they want an actor for an English or Irish character it's Gwyneth Paltrow or Brad Pitt.
Quack!
GtD.