American Airlines said a “technical issue” is delaying all of its flights in the United States during one of the busiest travel periods of the year.

“A technical issue is affecting American flights this morning,” an airline spokesperson told CNN. “Our teams are working to resolve the issue as quickly as possible, and we apologize to our customers for the inconvenience.”

The Federal Aviation Administration posted a nationwide groundstop order for all American flights at the request of the airline, according to an advisory notice.

Customers on social media began complaining early Tuesday morning that some flights were returning to their gates and that delays were about 90 minutes.

An AA representative on X said an “estimated timeframe has not been provided.” American Airlines was also seen replying to customer complaints on X.

In one reply, the company said, “Our team is working to get this rectified so that you can be safely on your way to your family. Your continued patience is appreciated.”

American Airlines’ (AAL) stock fell nearly 3% in premarket trading.

News4JAX will update this article as soon as we learn more information.