Ukraine is a country in Eastern Europe. It is the second-largest European country after Russia, which borders it to the east and northeast. It also borders Belarus to the north; Poland and Slovakia to the west; Hungary, Romania and Moldova to the southwest; with a coastline along the Black Sea and the Sea of Azov to the south and southeast. Kyiv is the nation's capital and largest city, followed by Kharkiv, Dnipro, and Odesa. Ukraine's official language is Ukrainian; Russian is also widely understood, especially in the east and south.