The presumption in the law is that every visitor visa applicant is an intending immigrant. Therefore, individuals applying for visitor visas must overcome this presumption. Applicants must demonstrate that they have a residence in Pakistan (or whatever your home country) which they do not intend to abandon, that they wish to enter the United States for a specifically limited period, and that the purpose of the trip is to enter the United States for business, tourism or medical treatment. There are many countries whose citizens do not require a visitors visa to enter the United States temporarily. Visa Waiver Program Unless previously cancelled, a visa is valid until its expiration date. While every applicant is looked at independently, some of the factors that affect the outcome of your visitors visa application are listed below: