Most US Visas are handled by U.S. Citizenship and Immigration Services (USCIS). This agency is the main authority for processing, approving, and denying US Visas applications. The agency also processes petitions from US employers seeking to bring a foreign worker to the United States. In addition to processing visas, USCIS keeps detailed records of all immigrants to the United States.
USCIS is a department of the United States Department of Homeland Security (DHS).