"The Department of State's Bureau of Consular Affairs is currently experiencing technical problems with our overseas passport and visa systems," an official statement said.
This issue is not specific to any particular country, citizenship document, or visa category, the State Department noted.
"We apologise for the inconvenience and are working urgently to correct the problem and restore full operability," it said.
This issue is affecting US operations at its missions in New Delhi, Mumbai, Kolkata, Chennai and Hyderabad.