Mexico, officially the United Mexican States is a federal republic in the southern half of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Covering almost two million square kilometers, Mexico is the sixth largest country in the Americas by total area and the 13th largest independent nation in the world. With an estimated population of over 120 million, it is the eleventh most populous country and the most populous Spanish-speaking country in the world while being the second most populous country in Latin America. Mexico is a federation comprising 31 states and a federal district that is also its capital and most populous city. Other metropolises include Guadalajara, Monterrey, Puebla, Toluca, Tijuana and León.