Effective April 5, the Visa Waiver Program (VWP) is being expanded to include citizens of Greece. VWP enables nationals of 36 participating countries to travel to the United States for tourism or business (B visitor purposes) for stays of 90 days or less without obtaining a visa. Note that just like all other VWP participants, Greek citizens must complete an Electronic System for Travel Authorization (ESTA) registration. Online resources include the steps to register for the ESTA program and a government FAQ sheet.