The western third of the island belongs to the Inuvik Region in the Northwest Territories and the rest is part of Nunavut 's Kitikmeot Region . It is nearly double the size of Newfoundland ( 111390 k ) , and is slightly larger than the island of Great Britain ( 209331 k. The western third of the island belongs to the Inuvik Region in the Northwest Territories ; the remainder is part of Nunavut 's Kitikmeot Region .