- US Department of State (www.travel.state.gov) Up-to-date visa and immigration information.
- US Department of Homeland Security (www.dhs.gov) Clear details on requirements for travel to the US; follow the How Do I?/For Travelers/Visit the US links.
- Visa Waiver Program (VWP; www.dhs.gov/visa-waiver-program-requirements) Though most foreign visitors to the US need a visa, the VWP allows citizens of 38 countries to enter the country for stays of 90 days or less without first obtaining a visa. Go to the website for a list of participating countries and detailed information.
- Electronic System for Travel (ESTA; https://esta.cbp.dhs.gov/esta) Visitors eligible for the VWP must apply for entry approval via ESTA. While it is recommended travelers apply at least 72 hours before travel, you may apply any time before boarding your flight and in most cases the process takes no more than half an hour.
- Passports Your passport should be valid for at least another six months after you leave the US.
Visitors from Canada, the UK, Australia, New Zealand, Japan and many EU countries don't need visas for stays shorter than 90 days. Citizens of other nations should check http://travel.state.gov.