A “technical issue” briefly disrupted American Airlines flights nationwide early on Tuesday, the airline said, at the start of a busy Christmas Eve for travelers around the country.

The Federal Aviation Administration said American requested a ground stop for all its flights. An hour later, American said flights were again beginning to board and the FAA lifted the nationwide ground stop.

“We’re currently experiencing a technical issue with all American Airlines flights,” the airline wrote in a post to X.

The post added, “Your safety is our utmost priority, once this is rectified, we’ll have you safely on your way to your destination.” Replying to questions from other social media users, the airline said it was not able to estimate how long the fix would take.

The airline wrote that it didn’t yet have a “timeframe” but that “they’re trying to fix it in the shortest possible time.”

In a statement sent to ABC News, the airline added, “Our teams are working to resolve the issue as quickly as possible, and we apologize to our customers for the inconvenience.”

The disruption will be unwelcome for a record number of Americans expected to travel across this holiday season. The Transportation Security Administration said it expects to screen nearly 40 million travelers from Dec. 19 to Jan. 2 — a 6.2% increase from 2023.

American Airlines said it was expecting Dec. 27 and Dec. 20 to be its busiest and second-busiest days, respectively, during its holiday period, which began on Dec. 18.

This is a developing story. Please check back for updates.

ABC News’ Ayesha Ali, Clara McMichael and Emily Shapiro contributed to this report.

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