TAMPA, Fla. (WFLA) —The U.S. Federal Aviation Administration’s (FAA) resumed flights across the country after an outage hit its computer system Wednesday morning.

The FAA had paused all domestic departures until 9 a.m. ET. after its Notice to Air Missions (NOTAM) system, which is responsible for helping pilots and aircrews plan flights, “failed.”

“Normal air traffic operations are resuming gradually across the U.S. following an overnight outage to the Notice to Air Missions system that provides safety info to flight crews. The ground stop has been lifted,” the FAA said in an updated notice. “We continue to look into the cause of the initial problem.”

President Joe Biden was briefed on the matter and spoke with Transportation Secretary Pete Buttigieg.

“They don’t know what the cause is,” Biden told reporters Wednesday morning. “I told them to report directly to me when they find out. Aircraft can still land safely, just not take off right now. They don’t know what the cause of it is, they expect in a couple of hours they’ll have a good sense of what caused it and will respond at that time.”

White House press secretary Karine Jean-Pierre tweeted that “there is no evidence of a cyberattack at this point, but the President directed DOT to conduct a full investigation into the causes.”