A U.S. visa in his/her passport gives a foreign citizen permission to apply to enter the U.S. A visa by itself doesn’t authorize entry to the U.S. A visa simply indicates that your application has been reviewed by a consular officer at an American embassy or consulate, and that the officer determined you’re eligible to travel to a U.S. port-of-entry for a specific purpose. The port of entry can be an international airport, a seaport or a land border crossing.

At the port-of-entry, a U.S. immigration officer of the Department of Homeland Security (DHS) decides whether to allow you to enter and how long you can stay for any particular visit, as part of the Admission process. Only the U.S. immigration officer has the authority to permit you to enter the U.S.