For USA it should either be the country name: the United States of America OR it should be the demonym: American. The last n is important. America is not any of those, and therefore the rules should be changes if America is being accepted.
It would be like saying that "Danes" is a country name. It simply isn't (there are probably better examples to show the difference).
USA is the country.
When we continue the conversation in Uzbek we'll use those conventions.
Although every country within north and south America are also americans.