The world's ( tenth longest river), world's tenth longest river, forming the border between the Russian Far East and Northeastern China. The Amur proper begins at the confluence of the Shilka and Argun rivers and is 1,755 mi (2,824 km) long. It flows east-southeast along the Russian-Chinese border to Khabarovsk, Siberia, and then northeast across Russian territory to empty into the Tatar Strait. Among its tributaries are the Zeya, Bureya, and Ussuri rivers.