Mongolia is a landlocked country in East Asia. Its area is roughly equivalent with the historical territory of Outer Mongolia, and that term is sometimes used to refer to the current state. It is sandwiched between Russia to the north and China to the south, where it neighbours the Inner Mongolia Autonomous Region. Mongolia does not share a border with Kazakhstan, although only 37 kilometres (23 mi) separates them. At 1,564,116 square kilometres (603,909 sq mi), Mongolia is the 18th-largest and the most sparsely populated sovereign state in the world, with a population of around three million people.