FAA Issues Rare Nationwide Ground Stop, Orders All Flights Halted

1:36 PM PT -- Peter Muntean, an Aviation Correspondent for CNN, predicts that this issue may last for days, with one or two days being needed to diagnose the issue.

1:28 PM PT -- U.S. Transportation Secretary Sean Duffy says the nationwide ground stop for all U.S. airports follows a communication issue impacting all Air Route Traffic Control Centers. He says FAA technicians are investigating the issue.

Travelers across America are going nowhere fast ... the FAA has ordered an extremely rare nationwide ground stop, bringing departing flights across the country to a screeching halt!

The Federal Aviation Administration issued the sweeping order Friday afternoon, citing "extraordinary circumstances" and "reasons of safety," according to U.S. Transportation Secretary Sean Duffy.

An air traffic control advisory states ... "All departing traffic should remain ground stopped until further notice."

And even international flights are caught up in the chaos ... the FAA says incoming international flights will be handled on a case-by-case basis.

The massive disruption comes as several major airports were already battling delays Friday, including Chicago's O'Hare and Midway airports, which were hit with ground stops tied to equipment outages.

Meanwhile, San Francisco International Airport reported average ground delays of more than two hours due to wind, while New York's LaGuardia Airport was also dealing with significant delays.