You're wasting your time trying to explain this to somebody who uses the derogatory "USian" to describe his supposed fellow countrymen.
But from your clarification it seem you simply meant American without any further qualifications.
Some people you just can't insult.
It's impossible to insult someone who refuses to be insulted.
That's not going to make anyone happy. It's Türkiye.
USAian.
Sounds cooler too because https://dragonball.fandom.com/wiki/Saiyan