 With the 1991 agreement, Russia transferred 9 km² (3.5 mi²) to China so that now the Sino-Russian border runs along the entire length of the river.The Khasansky District lies near the Sino-North Korean border and the Sino-Russian border and included two disputed regions along the Tumen River.According to the agreement, 3 km² (1 mi²) of territory would be transferred to China, and Chinese ships would gain the right to navigate the Tumen river.