HOUSTON, Texas (KTRK) -- A nationwide ground stop ordered by the Federal Aviation Administration on Friday affected flights at airports across the country, including Houston's George Bush Intercontinental Airport and William P. Hobby Airport.

The FAA said the ground stop was issued for all airlines because of an air traffic control communications issue impacting Air Route Traffic Control Centers nationwide.

The agency said all flights "will be handled on a case by case basis." Transportation Secretary Sean Duffy said the FAA ordered the nationwide ground stop "for reasons of safety" following the communications disruption and promised updates as more information becomes available.