You can join US servers. It's not always easy though, playing hours are a bit off compared to most Americans, but I never had that much of a problem finding people to do stuff with (mostly because I solo a lot though
).
Especially if you join a guild, always possible to just solo at times and try to see when the rest of the guild is online.
You just need to change the region select at the first "accept" screen, that'll cause a second one to appear but you'll be able to start a character on the US servers then.