American Airlines flights have received the all-clear to return flying after a brief technical issue grounded all its flights.

Earlier today, the Federal Aviation Administration (FAA) ordered all the airline's flights grounded in the US after the carrier reported a technical issue affecting its entire system.

A software fault appeared to be the cause of the shutdown, as a result of which boarding passes could not be scanned at the gates.

This comes as millions of people are traveling ahead of Christmas Eve.

AA's request for a "nationwide groundstop” was also acknowledged on the FAA's website

The airline confirmed the issue in a social media comment to a user, asking for passengers' "continued patience.”

After about an hour, the FAA allowed American Airlines flights to return to flying.

No reason was given for the technical issue, and the airline has not issued a statement explaining the glitch.

ftm/dj (dpa, Reuters, AP)