That's always a grey area. When i applied for my A&P my experience was on both Canadian and American registered aircraft, but they had no problem excepting my experience, same thing when it came to my AME license. a lot of the facilities i worked at were Easa approved, even though they weren't in Europe, so i don't know why they would deny my experience. i'm sure its more of a common sense thing. If you've been working in third world countries that lack any kind of recognized regulatory bodies then they might look down on your experience.