The US State Department said on Friday it was having technical problems with its overseas passport and visa systems, and was investigating the root cause of the issue.

Asked what caused the problems and whether it was a malicious action or hack, the State Department said: "We are working urgently to correct the problem and expect the system to be fully operational again soon."

The State Department said the issue was not specific to any particular country, citizenship document or visa category. Passport applications accepted overseas on or after May 26 were affected, it said, adding that passports for emergency travel could be issued.

The news comes as the United States deals with a cyber attack on the computer systems of the Office of Personnel Management.

The US Senate Intelligence Committee said on June 10 the massive theft of data appeared to have been state sponsored, although it stopped short of pointing the finger at China.

The White House said on Friday it would not confirm reports that as many as 14 million current and former US government employees had their personal information exposed to hackers. – Reuters