Mexico borders to the south of the United States.
No country borders the US to the west. The western border of the US is the Pacific Ocean.
No, Mexico borders the US as well.
Canada borders the United States to the north.
Canada
New Mexico. Mexico is a country bordering the United States and New Mexico, a state in the the United States, has the same name. The only state in the US that has the name of a country that borders the US in it is New Mexico. The other country is Mexico.
There is no country to the west of the United States. At some areas, Canada and Mexico borders the US to the west, but they are typically seen as the northern and southern borders respectfully.
Tennessee borders 8 states (as does Missouri), the most of any.
Kansas.
Illinois shares land borders with several other US states and one of the Great Lakes, but does not share a border with another country. It is possible, though, to travel by boat from Illinois to Canada.
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.
Ottawa is the capital city of Canada, the only country that borders both the Arctic Ocean and the United States.