Tourists arriving in the US must have a valid tourist visa. Unless your country participates in the visa waiver program (VWP) wherein you can arrive in the US for 90 days or less without applying for a visa in advance. The tourist visa has certain requirements: strong ties in the country as to compel the person to return home after the short stay, a valid purpose for the trip, and the funding source to pay for the trip.
Visitors traveling to the United States temporarily for business or pleasure typically arrive on a tourist visa. For specific purposes that are legitimate, such as for medical treatment, attend a business conference, an expo or fair, or certain types of training. Visitors can request a notation on their tourist visa indicating the purpose of their trip in the event that a visa extension or visa change is required later on.
Tourists from certain countries and who meet certain visa requirements may not have to apply for a visa in advance if they are a national from a country that is party to the Visa Waiver Program (VWP.) The VWP enables nationals of 36 participating countries to travel to the US for tourism or business (visitor B visa purposes only) for stays of 90 days or less without obtaining a visa. The program was established to eliminate unnecessary barriers to travel, stimulating the tourism industry, and permitting the Department of State to focus consular resources in other areas.
For individuals who are from countries not participating in the VWP, they will have to apply for a tourist visa at the US Embassy or Consulate in their country and request an interview appointment. Prospective visitor has to show strong ties, and a steady employment history, consistent income, and a valid and legitimate purpose for the trip.
The consular officer has a very short time to decide on whether the tourist applicant is qualified for the visa. The visa applicant will be questioned as to the intent and purpose of the trip, whether the applicant has violated any laws or visa violation in the past, and most importantly, the consular officer will determine based on the evidence submitted whether the applicant has strong ties to their home country.
The most frequent basis for refusal concerns the requirement that the prospective visitor possess a residence abroad he/she has no intention of abandoning. Applicants prove the existence of such residence by demonstrating that they have ties abroad that would compel them to leave the US at the end of the temporary stay. The law places this burden of proof on the applicant.