Wrong,
Mexico: "Americans"=Gringos
Argentina: USAnias=Yankees (Arg. yankis)
Argentina: Gringos=Italians (Particularly in the country side, La Patria Gringa)
From Wiktonary: The word "gringo" is used mostly as a synonym of "Italian" or a person with European ancestry, especially if the person is blonde, even when the person was raised and born in Argentina, it refers to their origin and color of hair. In here it's not used as an insult. People use it even as a normal nickname. For instance, El "Gringo" Heinze (Gabriel Heinze, Argentinian soccer player), just to mention one case between the many famous and ordinary people with that nickname.
Cheers