The Visa Waiver Program (VWP) enables nationals of certain countries to travel to the United States for tourism or business [visitor (B) visa purposes] for stays of 90 days or less (extension or change of status are not permitted) without obtaining a visa. See the U.S. Department of State Web site for more information. VWP eligible travelers may apply for a visa, if they prefer to do so. Not all countries participate in the VWP, and not all travelers from VWP countries are eligible to use the program. VWP travelers are screened prior to admission into the United States using a system called ESTA. You must complete your ESTA application before departing for the U.S.