This visa category is mostly for Diplomats and other foreign Government Officials traveling to the United States to engage solely in official duties or activities on behalf of their national government. Immediate family members of diplomats and government officials receive A-1 or A-2 visas, with few exceptions. Personal employees, attendants, or domestic workers for diplomats and government officials (holding a valid A-1 or A-2 visa) may be issued A-3 visas.
Government officials traveling to the United States to perform Non-Governmental Functions of a commercial nature, or traveling as tourists, require the appropriate visas and do not qualify for A visas.
Generally, interview is not required for this category, but U.S. Consulate can request. A3 requires interview.