North Korea, officially the Democratic People's Republic of Korea, is a sovereign state in East Asia constituting the northern part of the Korean Peninsula. Officially, its territory consists of the whole Korean Peninsula and its adjacent islands. Pyongyang is the nation's capital and largest city. To the north and northwest, the country is bordered by China and by Russia along the Amnok and Tumen rivers; it is bordered to the south by South Korea, with the heavily fortified Korean Demilitarized Zone separating the two. Nevertheless, North Korea, like its southern counterpart, claims to be the legitimate government of the entire peninsula.
In 1910, Korea was annexed by Japan. After the Japanese surrender at the end of World War II in 1945, Korea was divided into two zones, with the north occupied by the Soviets and the south occupied by the Americans. Negotiations on reunification failed, and in 1948, separate governments were formed: the socialist Democratic People's Republic of Korea in the north, and the capitalist Republic of Korea in the south. An invasion initiated by North Korea led to the Korean War.