See daily updates about this situation on the State Dept Facebook page.
Because of technical problems affecting the State Department’s consular systems, U.S. consulates are temporarily unable to issue visas or other travel documents. Foreign nationals who filed nonimmigrant visa applications or had visa interviews on or after June 9 will not be able to receive their visas until the problems are resolved.
If you submitted a visa application after June 9, you may need to resubmit your application or reschedule your appointment. The State Department has not estimated when consular systems will be back in operation.
What This Means for Visa Applicants
Foreign nationals with pending visa applications may have their U.S. travel plans delayed because of the system issues. Applicants who have been interviewed and are awaiting visa issuance can ask to have their passports returned, but will need to go back to the consulate for visa stamping once the State Department resolves its system problems.
If you are applying for an entry visa, make sure to read the information on the link above and communicate with the embassy/consualte about how the delay will impact your application.
Visit the link above for more information from the State Department and answers to questions.