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.
Ukrainians
Ukrainians (, "ukrayintsi", ) are an East Slavic ethnic group native to Ukraine, which is by total population the sixth-largest nation in Europe. The Constitution of Ukraine applies the term 'Ukrainians' to all its citizens. The people of Ukraine have historically been known as "Rusyns (Ruthenians)" and "Cossacks", among others. According to most dictionary definitions, a descriptive name for the "inhabitants of Ukraine" is "Ukrainian" or "Ukrainian people".