Generally, a citizen of a foreign country who wishes to enter the United States must first obtain a visa, either a nonimmigrant visa for temporary stay or an immigrant visa for permanent residence. Citizens of qualified countries may be also able to visit the United States without a visa under the Visa Waiver Program. If you do not qualify for the Visa Waiver Program or are traveling to study, work, or participate in an exchange program, you must apply for a nonimmigrant visa.