Airports in Lexington, Louisville and Northern Kentucky confirmed late Friday afternoon they have grounded all departing flights.
The move follows a rare stop order from the Federal Aviation Administration, citing "extraordinary circumstances and for reasons of safety."
In a tweet, Transportation Secretary Sean Duffy cited a communication issue affecting air traffic control.
Just after 4:30 p.m. Blue Grass Airport officials confirmed to WEKU they have grounded flights there, but said they did not have additional details.
In a statement, to WEKU Louisville Muhammad Ali International Airport encouraged passengers to check their flight status.
“The Louisville Muhammad Ali International Airport (SDF) is currently under the FAA-issued nationwide ground stop that was sent shortly before 4 p.m. ET due to a FAA communications issue. This means, at this time, no aircraft are permitted to depart SDF, and delays are expected for all flights whether scheduled to depart from or arrive to SDF."
Officials with Cincinnati Northern Kentucky International Airport also confirmed around 4:40 p.m. they had stopped departing flights.
This is a developing report.