I'm from the UK. My home address is in Bangor, Northern Ireland. Almost every employer (in the UK) I've interviewed at initially thought I was Welsh.

If I say "I'm from Bangor" to an American and they assume I'm American, which one of these would they think I'm referring to?[0] There are two separate Bangor Townships in Michigan alone.

It makes total sense to refer to the country and city/town when you are addressing an international audience.

[0] https://en.wikipedia.org/wiki/Bangor#United_States_of_Americ...