mexico
Tennessee borders 8 states (as does Missouri), the most of any.
The country that borders the south region could vary depending on the specific country you are referring to. Can you please provide more details so I can give you a more accurate answer?
The southwest region of the United States borders Mexico.
Colorado borders the mountain region.
First of all, South America is a continent, or at least a region of the Americas. It is not a country. Second, of the two, Canada borders the US.
Jordan borders the southwest region of Israel.
The costal plains
The Sahel borders the Sahara.
tidewater
Ladakh
The Americas 39% locally (with in US borders) 20% from Mexico and Venezuela 16% from Canada 72% of it comes from the western hemisphere.