The US aviation authority has cleared American Airlines flights to fly after a brief grounding disrupted the carrier's operations nationwide.

About 7am Tuesday, US Eastern time, the Federal Aviation Administration (FAA) ordered a halt on the carrier's domestic services after it reported a technical fault in its system.

"We're currently experiencing a technical issue with all American Airlines flights," the airline said in a post to X. 

"Your safety is our utmost priority, once this is rectified, we'll have you safely on your way to your destination."

The company has not issued a press release explaining the issue and an email by the Associated Press was not immediately returned.

A post on the FAA website acknowledged the airline's request for a "nationwide ground stop" for all American Airlines planes and their subsidiary airlines.

The groundings come amid a busy travel period with millions of people expected to fly over the next 10 days.

The Transportation Security Administration expects to screen 40 million passengers over the holidays and through January 2.

ABC/AP