Land boundaries: total: 12,048 km
border countries (2): Canada 8,893 km (including 2,477 km with Alaska), Mexico 3,155 km
note: US Naval Base at Guantanamo Bay, Cuba is leased by the US and is part of Cuba; the base boundary is 28.5 km
Definition: This entry contains the total length of all land boundaries and the individual lengths for each of the contiguous border countries. When available, official lengths published by national statistical agencies are used. Because surveying methods may differ, country border lengths reported by contiguous countries may differ.
Source: CIA World Factbook - This page was last updated on July 9, 2017