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.

“I equate a good, A-level, traffic controller that can handle a place like Newark, JFK, LAX, San Francisco, to a three dimensional chess player who can juggle a chainsaw, an axe, a sword, a razor blade with his eyes closed,” Aero Consulting Experts CEO and a former United pilot Ross Aimer told Fortune.

Similar to last summer, there is currently a nationwide shortage of air traffic controllers, which will “take time” to replenish, according to Transportation Secretary Sean Duffy.

Several times over the last year, Newark controllers lost radar or radio service, leaving them unable to talk with planes they were tracking.