Because of an old rule (plurals get double letter), I believe the recommended way by the Academy is «E.E. U.U.». Not sure if they’ve said otherwise recently.
It’s also not uncommon to see «E.U.A.», «E.U.» or those same but without the dots.
No confusion with the European Union, though, because that’s «Unión Europa»: «U.E.».
The United States of America is just a series of English words. It really wouldn’t make sense in some other languages.
In Spanish it’s Estados Unidos which seems like a translation of the words.
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Because of an old rule (plurals get double letter), I believe the recommended way by the Academy is «E.E. U.U.». Not sure if they’ve said otherwise recently.
It’s also not uncommon to see «E.U.A.», «E.U.» or those same but without the dots.
No confusion with the European Union, though, because that’s «Unión Europa»: «U.E.».
Finally we can get into Eurovision!
Do country names, or names in general, need to make “sense”?
As for the USA, without any evidence or desire to look it up, I think most languages translate it pretty much literally.