According to the World Atlas, the two countries with the longest shared international border are Canada and the United States. The border between the two countries is 8,891 km (5,525 mi) long and is the longest international border in the world.
The two countries with the longest shared international border are Canada and the United States. Their border stretches for over 8,891 kilometers (5,525 miles) from Alaska in the west to Maine in the east.
