Puerto Rico is a U.S. territory, not a sovereign nation. It is neither a state nor an independent country, leading to its omission from country lists.
It lacks widespread recognition as an independent state and is not a United Nations member.
"Country" can be defined strictly by sovereignty or more broadly by culture/geography. Lists using the strict definition exclude Puerto Rico despite its strong Latin American cultural ties.
While culturally and linguistically Latin American, Puerto Rico's unique political status often places it in a separate category.