Answer: A person seeking to visit the United States must generally obtain a visa from a U.S. consulate abroad. At the consulate, they will be required to overcome a presumption that they intend to immigrate or remain in the United States beyond the time of their intended visit or work illegally. An invitation letter is only one factor that may be considered in evaluating a person’s true intent when they seek to visit the United States. The foreign consul will generally scrutinize the person’s ties to their home country closely, and whether they have the economic means to full fill the purpose of their trip. People from certain countries are exempt from the visa requirement.