How many countries does the United States share a land border with?

The United States shares a land border with two countries: Canada and Mexico. The countries are located to the north and south respectively. The United States and Canada share the longest international land border in the world, stretching over 5,500 miles (8,891 kilometers) and passing through 13 U.S. states and 8 Canadian provinces/territories. On the southern side, the United States and Mexico share a border of approximately 2,000 miles (3,218 kilometers), which is one of the busiest and most traversed international borders globally.