United States Visas Information and Guide Travelocitiez:
A citizen of another country who wishes to enter the United States must obtain a US Visa. Upon approval, the USA visa documentation is placed in the foreign national's passport. A visa does not guarantee entry into the United States. Instead it determines the eligibility of the individual seeking to enter the United States. The Customs and Border Protection Agency, the CBP, a division of the Department of Homeland Security (DHS), will decide whether the foreign national with the approved USA Visa will be allowed to enter US or not.
A citizen of another country who wishes to enter the United States must obtain a US Visa. Upon approval, the USA visa documentation is placed in the foreign national's passport. A visa does not guarantee entry into the United States. Instead it determines the eligibility of the individual seeking to enter the United States. The Customs and Border Protection Agency, the CBP, a division of the Department of Homeland Security (DHS), will decide whether the foreign national with the approved USA Visa will be allowed to enter US or not.