American Airlines’ nationwide flights were briefly suspended Tuesday morning due to a technology issue, marking a difficult start to one of the busiest days for leisure travel.

The airline said in a post on X, formerly known as Twitter, that the issue was resolved as of 8:30 a.m. Arizona time. The airline offered customers traveling to or from 12 U.S. cities, including Phoenix, the option to change their flight without an additional fee if they book by Dec. 24.

“We sincerely apologize to our customers for the inconvenience and have issued a travel advisory to allow additional flexibility,” the airline announced.

Flights were prevented from taking off after the Federal Aviation Administration ordered a nationwide ground stop. According to the Associated Press, government officials cleared the flight for departure about an hour later.

Meanwhile, Phoenix Sky Harbor International Airport had reported one canceled and 70 delayed flights between Dec. 23 and 25 as of 11:30 a.m. Tuesday.

The canceled flight was to Oklahoma City, and the delayed flights were to various cities in the United States and Mexico, including Flagstaff, Dallas, Chicago, Monterrey and several cities in California and Hawaii, among other destinations.

Several flights were impacted by weather conditions, with rain and snow expected in the Pacific Northwest through Christmas Day. Thunderstorms also developed in the south, freezing rain was reported near Baltimore and Washington and snow fell in New York.

People can check the status of affected flights at skyharbor.com/flights/delayed-canceled-and-diverted-flights/ or directly with their airlines.

This article originally appeared on Arizona Republic: Here’s how weather and technical issues affected Christmas Eve travel