The Federal Aviation Administration ordered a rare nationwide ground stop Friday afternoon, halting all departing flights across the United States after a temporary telecommunications outage disrupted air traffic control systems.

The FAA said the order was issued “due to extraordinary circumstances and for reasons of safety.” Aircraft already in the air may land, while inbound international flights are managed case by case. Officials confirmed all flights have been accounted for.

Transportation Secretary Sean Duffy stated: “The FAA issued a nationwide ground stop for all U.S. airports following a communication issue impacting all Air Route Traffic Control Centers. FAA technicians are investigating the issue.”

Homeland Security Secretary Markwayne Mullin said there is “no indication yet that this was a nefarious attack against us. It’s just a telecommunications outage as of right now.” He added there is “no reason for the public to be afraid” and that no timeline has been set for lifting the stop.

This is the first nationwide ground stop since January 2023. The only earlier one followed the Sept. 11 attacks.

Thousands of flights have been delayed or canceled nationwide, with airlines warning of continued disruptions through the rest of the day and possible cascading effects afterward.

The order affects every U.S. airport. In the Rio Grande Valley, McAllen-Miller International, Valley International Airport in Harlingen, and Brownsville/South Padre Island International have all been impacted, with no departures allowed until the ground stop is lifted. Travelers should check directly with their airline for the latest updates.

Safety remains the top priority as FAA technicians work to restore full communications.