Air traffic controllers who do not report back to work immediately will be substantially “docked,” President Trump warned Monday, saying he’s disappointed with those who took time off during the government shutdown that may be on the verge of ending this week. 

Those air traffic controllers who showed up to work for the past 41 days will receive bonuses, the president pledged. 

One of the most dominant stories of the longest-running shutdown in history is the delays and cancellations of flights across the country. On Friday, the Federal Aviation Administration cut flights by 10 percent at 40 high-volume airports to deal with shortages of air traffic controllers.

The president’s announcement on Truth Social Monday comes as Congress appears close to passing a government funding agreement that would re-open federal agencies through the end of January, returning nonessential federal workers to their jobs and enabling essential workers whose pay had been suspended to receive back payments. 

The president made clear he has no patience for air traffic controllers who took time off during the shutdown, even though many unpaid controllers took part-time jobs to cover essentials during the showdown on Capitol Hill.

“All Air Traffic Controllers must get back to work, NOW!!! Anyone who doesn’t will be substantially ‘docked,’” the president wrote on Monday. “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. You didn’t step up to help the U.S.A. against the FAKE DEMOCRAT ATTACK that was only meant to hurt our Country.”

Mr. Trump says that those controllers “will have a negative mark, at least in my mind, against your record.”

The president did offer some praise to the controllers who took no time off. He called them “GREAT PATRIOTS,” and declared that he will be “recommending a BONUS of $10,000 per person for distinguished service to our Country.”

Mr. Trump went further against air traffic controllers who took time off during the shutdown, urging them to “leave service in the near future” if they want to do so. Those who now want to quit will receive “NO payment or severance of any kind!”

“You will be quickly replaced by true Patriots, who will do a better job on the Brand New State of the Art Equipment, the best in the World, that we are in the process of ordering,” Mr. Trump said. 

The National Air Traffic Controllers Association — which is the main union that represents America’s aviation safety professions — did not immediately respond to a request for comment about the president’s threats. 

According to data from FlightAware, cancellations and delays at airports across the country are only getting worse as the shutdown persists. By midday Monday, nearly 18,000 flights had been delayed across the country, while more than 2,100 flights had been canceled. The same data shows that more than 1,000 flights have already preemptively been canceled on Tuesday. 

Just in the last 72 hours, more than 70,000 flights faced delays and nearly 10,000 were canceled. The shutdown has had a dramatic impact on flights not only domestically, but also for travelers trying to return to the United States. 

During an interview with CNN’s “State of the Union” on Sunday, Secretary Sean Duffy warned that a significant number of Americans would likely miss Thanksgiving with their families this year if the shutdown drags on. 

“I think the number is going to be substantial,” Mr. Duffy said. “You look at the trend line … and it’s only gotten worse as we’ve gone through the shutdown.”

“To answer your question, it’s only going to get worse,” he said.