U.S. Transportation Secretary Sean Duffy threatened Tuesday to take “action” against air traffic controllers who are absent from their posts because they are not receiving a paycheck due to the government shutdown, the longest in history.

Initially, Duffy urged air traffic controllers to return to work.

He assured them they would receive 70% of their pay within 24 to 48 hours of the government reopening. “I encourage everyone to come to work,” Duffy said, urging them to “be patriotic” and help maintain airspace safety. Duffy made these remarks after President Donald Trump announced Monday that he intends to cut the pay of controllers who are not showing up for work and provide a $10,000 bonus for those who do. “I am concerned about your dedication. I am concerned about your patriotism. We haven’t made a decision yet, but we are going to look at those controllers who have repeatedly chosen not to report to work,” Duffy said from Chicago’s airport. “I am trying to hire more air traffic controllers, not lay them off, but if we have controllers who are consistently not doing their jobs, we will take action,” he added. The Secretary He stated that control towers experienced fewer staffing problems because most workers “see the end of the shutdown near and feel more optimistic,” after the Senate advanced a resolution to reopen the government. The federal government shutdown, which at 42 days is the longest in history, is especially impacting air travel, as thousands of controllers who are not receiving a salary are absent every day citing health reasons. The shortage of controllers forced the Trump Administration to order a 10% reduction in air traffic at the country's 40 largest airports, which has resulted in a wave of flight delays and cancellations. More than 1,Two hundred planes were grounded on Tuesday and another 3,200 experienced delays, as Americans grow increasingly worried about the approaching Thanksgiving holiday at the end of November. After several weeks of failed attempts, the Senate on Monday passed, with the support of a group of rebel Democrats who joined Republicans, a budget extension to reopen the government, a bill that now needs to be approved by the House of Representatives and signed into law by Trump.