Japanese–Russian relations refers to the bilateral international relations between Japan and the Russian Federation. Relations between Russia and Japan are the continuation of the relationship of Japan with the Soviet Union from 1917 to 1991, and with the Russian Empire from 1855 to 1917. Historically, the two countries had cordial relations until a clash of territorial ambitions in the Manchuria region of northeastern China led to the Russo–Japanese War in 1904, ending in a Japanese victory which contributed to the weakening of the monarchy in Russia. Japan would later intervene in the Russian Civil War from 1918 until 1922, sending troops to the Russian Far East and Siberia. That was followed by border conflicts between the new Soviet Union and the Empire of Japan throughout the 1930s. The two countries signed a nonaggression pact in 1941, although the Soviet government declared war on Japan anyway in August 1945, invading the Japanese puppet state of Manchukuo as well as seizing the Kuril chain of islands just north of Japan. The two countries ended their formal state of war with the Soviet–Japanese Joint Declaration of 1956, but as of December 2020 have not resolved this territorial dispute over ownership of the Kurils.