i'm just some random nobody paco. but. i think it would be fair for both nations to call it gulf of america, or as you said "gulf of the americas" even though to me that implies both north and south america. not just north america. of course if mexico decided to follow our lead, they could easily rename the united states to "bum fucked egypt". what could we do to stop you? it's just a consensus of people agreeing on a name. i still call kiev, kiev.
United States