hello hrafndot, if i'm not mistaken, persona only verifies your email-address once you log into a service. if a site is asking for your location, this is something independent/on top of persona and depends on the options a site is implementing.

Where do you want to change the country?

Are you talking about:

Mozilla Foundation(US)

Persona (as part of firefox tools) verified my gmail address. It offered only USA when I was registering. Because my gmail is .com, maybe this is misleading. I will try again, thanks for helping anyway.

manojit, I am in FF android 26.0.0 on Samsung note2. ff is default browser. I choose Tools which contains add-ons and apps. when I choose apps it takes you to marketplace which then offers persona. Thats when the region/country starts and it doesnt give a choice. Thanks for helping, anyway.