Yes, North or South Americans. but the only country in the Americas that has America in its name is the USA.
And lost in the loud PC babbling of the ignorant, is the fact that the habit of all other countries of the America continent the refer to U.S> citizens as "Americans" is what induced the common shortcut.
As usual, the PC imbeciles infer the most sinister motives for the popular shortcut, even though in the most remote corners of the earth "I am an American" is instantly understood correctly.