Bolshoy Ussuriysky Island

Since the Sino-Russian Border Agreement that was fully implemented in 2008, Bolshoy Ussuriysky Island was divided between China and Russia.

[b] Its position at the confluence of the Amur and the Ussuri, and right next to the major Russian city of Khabarovsk, has given it great strategic importance.

The Soviet Union forcefully occupied Bolshoy Ussuriyskiy and Yinlong Islands in 1929 in the wake of a Russo-Manchurian conflict, but this was not accepted by China.

[1] On 14 October 2004, the Complementary Agreement between the People's Republic of China and the Russian Federation on the Eastern Section of the China-Russia Boundary was signed, in which Russia agreed to relinquish control over Yinlong Island and around half of Bolshoy Ussuriysky.

[citation needed] In return, mainland China agreed to drop all territorial claims to the remainder of Bolshoy Ussuriysky kept by Russia and received the right to navigate ships along the main channel of the Amur.

[citation needed] In 2005, the Russian Federal Assembly and the mainland Chinese National People's Congress approved the Sino-Russian Border Agreement.

On 21 July 2008, an agreement was signed in Beijing by the mainland Chinese and Russian Foreign Ministers that finalized the border demarcation and formally ended negotiations.

Therefore, the ROC still formally claims all parts of the Heixiazi Islands, as it does not consider border treaties signed by the PRC with other countries to be valid.