The Biden administration is to blame for the ongoing air traffic control failures at New Jersey’s Newark Liberty International Airport, and throughout the system, Department of Transportation Secretary Sean Duffy said Monday.

The Newark airport had hundreds of flights delayed following a telecommunications issue on Sunday, just two days after a brief outage happened on Friday.

At times Monday evening, as few as three air traffic controllers per hour were lined up to monitor via radar the planes flying into and out of the airport, the Federal Aviation Administration said.