Trump says he will change the name of the Gulf of Mexico. Can he do that?

President-elect Donald Trump said Tuesday that he would move to try to rename the Gulf of Mexico to the “Gulf of America,” a name he said has a “beautiful ring to it.”

It’s his latest suggestion to redraw the map of the Western Hemisphere. Trump has repeatedly referred to Canada as the “51st State,” demanded that Denmark consider ceding Greenland, and called for Panama to return the Panama Canal.

Here’s a look at his comment and what goes into a name.

Why is Trump talking about renaming the Gulf of Mexico?