North Korea–Russia border

A border by inference

Russia took the Maritime Province, east of Manchuria and Korea, under the Treaty of Peking of 1860. That treaty ran the China–Russia boundary down to the Tumen River 20 versts (13.2 miles) above its mouth, so the rest of the river to the sea became, by inference, the boundary between Russia and Korea.^[1]

In 1886 China and Russia replaced their rotted wooden pillars, and moved the last one, pillar “T”, to a point 30 li (about 10.4 miles) from the sea, shortening the Korean stretch to its present length.^[1]

Korea and Russia never signed a treaty drawing the line. On 20 August 1888 they agreed regulations on trade on the Tumen that spoke of the river as “their common frontier” and let both countries’ coastal ships sail it freely. Japan annexed Korea in 1910; in 1914 it proposed using the main channel as the boundary, but the First World War and the Russian Revolution stopped any agreement.^[1]

“Russian and Corean coasting-vessels shall be free to navigate the River Tumen at pleasure.”^[1]

A river in the marshes

The lower Tumen runs through flat, swampy land full of small lakes and lagoons. It is about a third of a mile wide at the Chinese tripoint and more than a mile wide at its mouth, and its silt builds islands and sandbars that shift with the water level. In 1965 the US Geographer knew of no dispute: the boundary was taken to follow the river’s main navigation channel.^[1]

Bridges

For decades the link was a rail bridge built in the 1950s.^[2][1] Vladimir Putin and Kim Jong Un agreed to build a road bridge at a 2024 summit in Pyongyang, the same year the two countries signed a mutual defence treaty.^[2] Construction began on 30 April 2025, when Russia’s prime minister, Mikhail Mishustin, called it a milestone in relations.^[3]

The two-lane, one-kilometre bridge opened on 7 September 2026, after delays on the Russian side. Named after Yakov Novichenko, a Soviet officer who shielded Kim Il Sung from a grenade in 1946, it cost 9 billion roubles, and its checkpoint is designed for up to 300 vehicles and 2,300 people a day.^[2]