Citizens of foreign countries that are eligible to participate in the Visa Waiver Program (VWP) may be able to travel to the United States for up to 90 days without a US visa if they meet all of the criteria, including possessing a valid Electronic System for Travel Authorization (ESTA).
The list of countries eligible for the Visa Waiver Program (as of November 2019) include: Andorra, Australia, Austria, Belgium, Brunei, Chile, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Monaco, Netherlands, New Zealand, Norway, Poland, Portugal, San Marino, Singapore, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, Taiwan, and United Kingdom. NOTE: In order to qualify for the VWP, citizens of the United Kingdom need to have an unrestricted right to permanent residence in England, Wales, Scotland, Northern Ireland, the Isle of Man, or the Channel Islands.
In addition to being a citizen of a country that is eligible for the Visa Waiver Program and possessing a valid Electronic System for Travel Authorization (ESTA), the purpose for travel to the USA must be allowed on a B-Visitor Visa. Examples include to consult with a business associate; negotiate a contract; attend a brief training program; attend a conference or convention (e.g., business, educational, professional, scientific); tourism/vacation; visit family or friends; receive medical treatment; take part in amateur contests or events (e.g., musical, sports, etc.). In most cases, a foreign national who travels to the USA under the VWP must possess a passport that will be valid for a minimum of six months following the planned date of departure from the United States.
The Visa Waiver Program does not allow a foreign national to: work in the USA; study in the US for credit; work in foreign media (e.g., film, journalism, radio, television) in the United States; or maintain permanent residence in the USA.
Please note that citizens of Canada or Bermuda generally do not need a temporary non-immigrant visa to visit the United States; however, there are some exceptions to this general rule.