It looks like it is an EU compliance issue which the US exchanges seem less than concerned about meeting which is understandable in view of how much trading is done that is not from the EU. If your broker is prepared to class you as "A sophisticated investor" then you will be allowed to trade US ETFs. However, they often want a large balance in your account first but either way it is worth asking them how you can comply with what is needed to be able to trade these instruments.