The Office of Visa Services, in the Consular Affairs Bureau, Department of State provides various functions:
When to Contact Us vs. Department of Homeland Security (DHS)
Defining the different roles and responsibilities of the Department of Homeland Security and the Department of State can be confusing. We hope this information will assist you:
Contact the Department of State - A U.S. Embassy or Consulate abroad will be your resource for questions about U.S. visas, including the application process, the status of visa processing, and for inquiries relating to visa denial.
Visa Services, Public Inquiries can usually explain what aspects of immigration law and regulation are applicable in certain cases, and can also check the current status of a particular case, if processing has been delayed.
Contact the Department of Homeland Security (DHS) - The Department of Homeland Security is responsible for the approval of all immigrant and nonimmigrant petitions, the authorization of permission to work in the United States, the issuance of extensions of stay, and change or adjustment of status while you are in the United States. Questions about these matters should be referred to DHS, U.S. Citizenship and Immigration Services (USCIS).