Burkina Faso is a landlocked country in West Africa. It covers an area of around 274,200 square kilometres (105,900 sq mi) and is surrounded by six countries: Mali to the north; Niger to the east; Benin to the southeast; Togo and Ghana to the south; and Ivory Coast to the southwest. Its capital is Ouagadougou. In 2017, its population was estimated at just over 20 million. Burkina Faso is a francophone country, with French as the official language of government and business. Formerly called the Republic of Upper Volta (1958–1984), the country was renamed “Burkina Faso" on 4 August 1984 by then-President Thomas Sankara. Its citizens are known as Burkinabé (/bɜːrˈkiːnəbeɪ/ bur-KEE-nə-beh).