Ammon News - Flights across the United States were grounded Wednesday morning after the Federal Aviation Administration said it experienced a computer outage.

All flights in the U.S. were grounded following the incident, a source with knowledge of the situation told NBC News. The FAA said later Wednesday morning it had ordered all airlines to pause domestic departures until 9 a.m. ET.

The FAA had said in a notice on its website that its Notice to Air Missions (NOTAM) system had "failed" Wednesday morning. A NOTAM is a notice containing information essential to workers involved in flight operations.

More than 1,200 flights within, into and out of the U.S. were delayed as of around 7 a.m. Wednesday morning, according to online flight tracker FlightAware. Just over 100 flights were listed as cancelled.

"Operations across the National Airspace System are affected," the FAA said in a statement.