Canada is a federal parliamentary democracy and a constitutional monarchy, with Queen Elizabeth II of the United Kingdom as its head of state. The country is officially bilingual at the federal level, meaning that citizens have the right to communicate with the government in either English or French. Immigration to Canada has made it one of the world's most ethnically diverse and multicultural nations. Its economy is the eleventh largest in the world, and relies mainly on natural resources and well-developed international trade networks. Canada's relationship with its neighbor and biggest trading partner, the U.S., has a big impact on its economy and culture.