Citizens of these countries need only a valid passport and a round-trip air or cruise ticket in their possession upon arrival. If they first enter the United States, they may also visit Mexico, Canada, Bermuda, and the Caribbean islands and return to the United States without a visa.
Further information is available from any U.S. embassy or consulate.
Usually you can obtain a visa at once or within 24 hours, but it may take longer during the summer rush from June through August. If you cannot go in person, contact the nearest U.S. embassy or consulate for directions on applying by mail. Your travel agent or airline office may also be able to provide you with visa applications and instructions.