Argentina is a federal state subdivided into twenty-three provinces, and one autonomous city, which is the federal capital and largest city of the nation, Buenos Aires. It has an estimated population of 46.4 million and a land area of 2,780,400 km2 (1,073,500 sq mi) making it the second-largest country in South America after Brazil. Argentina has identified sustainable transport as a key national objective, with a comprehensive package of sustainable transport activities currently envisioned.