I dunno what Spanish speaking country you’re from, but every Spanish speaker I’ve ever known has used “America” to casually refer to the USA.
Soy de México y le dicen Estados Unidos en todo latino América
Here’s a meme from a chilean cartoonist:
You can also check the Wikipedia page under the section “Number”
https://en.wikipedia.org/wiki/Continent
The six-continent combined-America model is taught in Greece and many Romance-speaking countries—including Latin America.[34][42]
Have you really ever heard someone from Jalisco or whatever refer to themselves as “American”?