To be an Actor means to be the most truthful to oneself that one can be, which is also learning to change and get away from oneself as much as possible. This dualism, that perhaps might appear like schizophrenic symptoms to some people, is also seen by others as a great incentive to go and work on the set of skills that are necessary to an actor.
This premise is to introduce a very discussed subject in the acting community: the subject of Accents. For many people being able to perform naturally and truthfully in an accent different to the natural one is a prerequisite to work. This part of the job, once all the pressure of sounding perfect has been taken away, can actually be great fun.
It’s all well and good to have an American actor playing British, or a British actor playing American: the subject becomes a tad more complicated when we take into consideration a foreign actor trying to play either of the aforementioned, though. I would like, here, to take the most neutral stance possible and look at the facts (which really kind of apply to native speakers learning Standard English or RP as well, and indeed any actor in any country trying to learn the standard diction of their language):
Fact number one: it is usually extremely hard to pass for someone who grew up and spoke in a different language all their life. However, as the lovely Audrey Hepburn one said "Nothing is impossible. The word itself says it: I’m possible".
Fact number two: there are thousands of native English and American actors out there, who were born and grew up in a completely British or American environment. Now, should foreign actors try and be as good at American and British English as the real deal is? I think this one really depends on how heavy your natural accent is, what's your typecast and also -- and especially -- do you WANT to pass for a native English actor at all? The decision is yours, and it's a very important marketing decision, believe me.
Fact number three (and probably the most important one): being an immigrant shouldn’t be considered as having something less than the national people, quite the contrary! Being a foreigner means having something more to offer. First of all, for the simple fact you are able to fluently speak at least one other language; secondly, a foreigner brings their own culture with them (with its ways of seeing the world, its food culture, its sense of humour...); and thirdly, living in a different country helps you understand the new culture: being an immigrant makes you more open-minded, more flexible and more available to change. All great attributes for actors! (So perhaps also take this advice: travel and live abroad, if you can!)
Going back to the main point of this post: accents. We are all for learning a new skill and getting as good as possible at it. So go for it! Try to neutralise your natural accent as much as you can (and this goes for both native speakers and foreigners), try and play someone different to who you are, go and work on your skills with joy and curiosity. But never, NEVER pretend to be someone that you are not, never apologise for who you are and where you come from, never think that you are less because you are different. Diversity is really the one thing that we all have in common.
Having said that, I shall now leave you to go and practice my RP.