American Airlines resumes flights after nationwide 'technical issue'

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.

"A vendor technology issue briefly affected flights this morning," American said in a statement sent to ABC News. "That issue has been resolved and flights have resumed."

"We sincerely apologize to our customers for the inconvenience this morning," the statement added. "It’s all hands on deck as our team is working diligently to get customers where they need to go as quickly as possible."

An American Airlines passenger plane is parked at a gate at Philadelphia International Airport in Philadelphia, Pennsylvania on Dec. 13, 2024. Daniel Slim/AFP via Getty Images

The airline flagged "a technical issue with all American Airlines flights," in a post to X early on Tuesday.

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.