Australia is a federation of six states, together with ten federal territories. The Australian mainland consists of five of the six federated states and three of the federal territories. The state of Tasmania is an island about 200 kilometres (120 mi) south of the mainland. The remaining seven territories are classified for some purposes as "external" territories. Aside from the Australian Antarctic Territory, which is Australia's claim to part of Antarctica, Australia is the world's sixth-largest country by total area.