If you are not Citizen of a country which is not in the list of visa exempt countries for the United State you must apply for a permission to be travel to the U.S . the list of visa exempt country can be found in USCIS website.To enter United State temporary as a tourist you need to obtain a B category visa . B visas are one of the non-immigrant visas granted by United State to applicant who wish to travel to the U.S for a certain period of time.Business tourist visa (B-1 ) is issued by the U.S government who wish to come to the U.S for business and for a short period of time . Thoese applicants who are invited to a congress or to have business meetings in the U.S seek B-1 temporary visa. Tourist visa for the U.S (B-2 tourist visa) is only issued for people who wish to come to the U.S only for pleasure and to visit this country as a tourist.
B1/B-2 Visas are normally valid for 6 months and if the applicant has not violated the rules and condition of the U.S government may extend it for another 6 months.
The processing and the validity of this category of temporary business/visa tourist visa (B-1/B-2) varies for different countries.
B2 USA Tourist Visa | Tourist Visa for USA