Gyeongui Line (1904–1945)
Following Japan's defeat in the Pacific War and the subsequent partition of Korea, the Gyeongui Line was divided at the 38th parallel between North and South Korea. On 25 August 1945, the Soviet Army began operating trains on the line north of Sariwon, whilst trains in the south terminated at Gaeseong. In 1946, the railways in both North and South were nationalised, creating the Korean National Railroad in the South and the Korean State Railway in the North. After the Korean War, the Gyeongui Line was split into three sections. In the South, the Seoul–Jangdan section became the KNR's Gyeongui Line, retaining the same name; in the North, the Bongdong–Pyeongyang section became the P'yŏngbu Line, whilst the Pyeongyang–Sinuiju section became the P'yŏngŭi Line.
North Korea–Russia relations
Diplomatic relations between North Korea (Democratic People's Republic of Korea, DPRK) and the Soviet Union (Union of Soviet Socialist Republics, USSR, the predecessor state to the Russian Federation) were first established on October 12, 1948 shortly after the Democratic People's Republic of Korea was proclaimed. During the Korean War, the Korean People's Army was supported by the Soviet military forces. North Korea was founded as part of the Communist bloc, and received major Russian support. China and the Soviet Union competed for influence in North Korea during the Sino-Soviet split in the 1960s, as the North Korea tried to maintain good relations with both countries.