Belarus–Ukraine relations
Belarus–Ukraine relations (, "Byelaruska-ŭkrainskiya adnosiny", , "Ukrains'ko-Bilorus'ki vidnosyny", , "Belorussko-ukrainskiye otnosheniya") are foreign relations between Belarus and Ukraine. Both countries were successively ruled by the Polish-Lithuanian Commonwealth, the Second Polish Republic, and ultimately, the Russian Empire. Prior to the 1991 breakup, both countries were part of the Soviet Union as the Belarusian SSR and Ukrainian SSR when they were the founding members of the United Nations in 1945. Being Slavic nations, both Belarus and Ukraine share closely related cultures and are predominantly inhabited by the East Slavic ethnic groups of Belarusians and Ukrainians respectively, along with a few Russians. Today, the two countries share an 891–km border.
Ukrainian Soviet Socialist Republic
Geographically, the Ukrainian SSR was situated in Eastern Europe to the north of the Black Sea, bordered by the Soviet republics of Moldavia, Byelorussia, and the Russian SFSR. The Ukrainian SSR's border with Czechoslovakia formed the Soviet Union's western-most border point. According to the Soviet Census of 1989 the republic had a population of 51,706,746 inhabitants, which fell sharply after the breakup of the Soviet Union. On January 1, 2018, according to the State Statistics Committee of Ukraine the population of the country was 42,216,766 permanent residents.