 Following a series of negotiations held in Beijing in 1924–1925, Japan agreed to extend diplomatic recognition to the Soviet Union, and to withdraw its troops from the northern half of Sakhalin island.In return, the Soviet Union agreed to honor the provisions of the Treaty of Portsmouth and to re-examine all other treaties between the former Russian Empire and Japan, including the Fishery Convention of 1907.The treaty was signed by Lev Mikhailovich Karakhan of the Soviet Union and Kenkichi Yoshizawa of Japan on 20 January 1925.