United States of America. Not the whole 3 continents.

Not in conventional usage.

> United States of America /əˈmɛrɪkə/ (USA), commonly known as the United States (U.S.) or America, -https://en.wikipedia.org/wiki/United_States

This is weird, not just because you forgot how many American continents there are, but because when people get bothered about calling the USA "America," it usually turns out to be because they consider America to be a single continent, north and south together, whose name the USA is usurping. If you prefer dividing it into North America and South America, then there's no confusion with plain America.

In other words, you should have said "Not the whole one continent."

North America is also Canada

Never said it wasn't.

You're right, I misread your comment (I thought that you were saying that using "North America" makes it obvious that this is the USA - which you did not). Sorry (as they say in Canada :))

What 3 continents?

North, South, and In.

I assume he meant regions with the third region being "Central America".