The U.S. Department of Homeland Security now requires travelers visiting the United States from countries participating in the Visa Waiver Program to obtain security clearance through the Web-based Electronic System for Travel Authorization program

. DHS said it would "take a reasonable approach to travelers who have not obtained an approved travel authorization via ESTA, and will continue an aggressive advertising and outreach campaign throughout 2009." The U.S. Travel Association stated concerns related to a lack of awareness among affected travelers, ramifications of noncompliance and complications for travelers and travel agents without Internet access.