The Democratic People's Republic of Korea, commonly referred to as "North Korea", is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea. The Amnok, or Yalu, and the Tumen rivers form the border between North Korea and China. A section of the Tumen River in the far northeast is the border with Russia.