An aircraft controller works in the tower at Ronald Reagan Washington National Airport in Arlington, Virginia, on November 7.

President Donald Trump demanded Monday that all air traffic controllers “get back to work, NOW,” warning that those who don’t would face penalties while promising bonuses for those who have worked during the government shutdown.

“Anyone who doesn’t will be substantially ‘docked.’ For those Air Traffic Controllers who were GREAT PATRIOTS, and didn’t take ANY TIME OFF for the ‘Democrat Shutdown Hoax,’ I will be recommending a BONUS of $10,000 per person for distinguished service to our Country,” Trump wrote on Truth Social, going on to add that those who didn’t work “will have a negative mark, at least in my mind, against your record.”

After the worst weekend for air traffic control staffing since the shutdown began, delays due to staffing problems were already reported Monday morning, despite a potential deal to end the government shutdown. Controllers are required to show up for their job during the shutdown but are not being paid.

Trump’s own Transportation Secretary Sean Duffy has said controllers were considering taking second jobs to make ends meet. He had previously cited controllers talking about driving for rideshare companies like Uber or delivering food on DoorDash to pay bills.

Trump on Monday also urged any controllers who wish to leave to do so, without “payment or severance of any kind,” adding that they would be replaced by “true patriots.”

“For those that did nothing but complain, and took time off, even though everyone knew they would be paid, IN FULL, shortly into the future, I am NOT HAPPY WITH YOU,” Trump wrote.

“If you want to leave service in the near future, please do not hesitate to do so, with NO payment or severance of any kind! You will be quickly replaced by true Patriots,” he added.