The United States is a federal constitutional republic consisting of 50 states and a federal district. The capital is Washington DC located in the middle of North America. The United States is bordered by the Pacific Ocean to the west, the Atlantic Ocean to the east, Canada to the north, and Mexico to the south. The state of Alaska is located in the northwest region of the North American continent, bordering Canada to the east. The state of Hawaii is located in the middle of the Pacific Ocean. The United States also has 14 territories, also known as national waters, scattered throughout the Caribbean Sea and the Pacific Ocean. New York is the largest city in the United States. With 9.83 million square kilometers, the United States is the third largest country in terms of area after Russia and China. Because the US has a large area and large terrain, almost There are all kinds of climates. The climate is temperate in most regions, tropical in Hawaii and southern Florida, polar in Alaska, Mediterranean in coastal California.