The term "African American" is complicated. But I think when someone self-identifies as a [country]-American, it's generally fair to call them an export of that country. You would want to be clear in certain circumstances that they weren't born there, but it's not a terrible way to phrase things.

Note that this is different from just having heritage in a country. There's immigration only a couple generations back in my family, but it's already mixed to the point that I wouldn't call myself any specific country-American.