The only country with a land border with the southern US is Mexico. However, some other nearby countries are Cuba and the Bahamas.
Canada to the north and Mexico to the south share land borders with the United States.
Canada and Mexico
Mexico, Canada and Russia (the closest distance from the USA to Russia is 3.8km)
The only country that borders Canada on land is the United States. American states that border Canada on land include Washington, Idaho, Montana, North Dakota, Minnesota, Michigan, New York, Vermont, New Hampshire, and Maine.
America is a country. There are not other countries within the United States.
Mexico or Canada are the United State's two main land borders.
Canada only borders one country: the United States.
States DO have borders, they are just not marked on land as they are not international.
States DO have borders, they are just not marked on land as they are not international.
Russia, China, and the United States by land area; Russia, Canada, and the United States by total area.
Hawaii, being made out of islands, has no land borders.