The Federal Aviation Administration delayed all domestic airline departures to at least 9:00 am ET in response to a nationwide technical malfunction that has affected hundreds of flights across the United States.

"The FAA is still working to fully restore the Notice to Air Missions system following an outage. The FAA has ordered airlines to pause all domestic departures until 9 am ET to allow the agency to validate the integrity of flight and safety information," the agency shared in a Twitter post on Wednesday.

United Airlines grounded all of its flights in the US earlier today following the system outage.