More than 3,000 flights were delayed and at least 1,600 were canceled into, within, or out of the United States on Nov. 10 amid the government shutdown, as President Donald Trump called on air traffic controllers to return to work.

As of 11 a.m., 3,303 flights were delayed and 1,671 were canceled, said FlightAware. Major U.S carriers—including American Airlines, JetBlue, Southwest, Delta Air Lines, and United—were experiencing significant delays or cancellations.

In a post on Truth Social, Trump said that air traffic controllers should return to work on Nov. 10 and that he will reward those who did not take any time off during the 41-day federal government shutdown.

“All Air Traffic Controllers must get back to work, NOW!!! Anyone who doesn’t will be substantially ‘docked,’” Trump wrote on social media.

The president then wrote that any controllers who “want to leave service in the near future, please do not hesitate to do so,” adding that they will get “NO payment or severance of any kind.”

The disruptions come about three days after the Federal Aviation Administration (FAA) initiated sweeping flight reductions at major American airports in a bid to keep the skies safe, as numerous air traffic controllers have been unable to get paid because of the shutdown.

The FAA had said that many controllers have been putting in long hours and mandatory overtime while lawmakers are at a standstill over how to reopen the government. Major hubs such as New York City, Los Angeles, and Chicago are among those affected by the cuts.

Some senators indicated on the evening of Nov. 9 that they had reached a deal to end the shutdown, overcoming a 60-vote procedural hurdle to pass a stopgap measure. At the same time, the Senate advanced a bill to end the shutdown, setting up the prospect of a vote to end the funding lapse by the evening of Nov. 10.

If the Senate eventually passes the amended measure, it still must be approved by the House of Representatives and sent to Trump for his signature, a process that could take several days.

“It looks like we’re getting very close to the shutdown ending,” Trump told reporters at the White House before the vote on Nov. 9.

The shutdown began on Oct. 1 and became the longest in history earlier this month.

Even if a shutdown measure is passed, airport disruptions could last longer than it takes to reopen the government, Transportation Secretary Sean Duffy said on Nov. 9.

“It’s going to be harder for me to come back after the shutdown and have more controllers controlling the airspace,” Duffy told CNN’s “State of the Union.” “So this is going to live on in air travel well beyond the time frame that this government opens back up.”

The FAA instructed airlines to cut 4 percent of daily flights at 40 major airports starting last week because of air traffic control safety concerns. Reductions in flights are mandated to reach 6 percent on Nov. 11 and then 10 percent by Nov. 14.

Several thousand flights were delayed or canceled on Nov. 7, Nov. 8, and Nov. 9 amid the shutdown and FAA cuts. A winter storm in Chicago is also likely disrupting air travel in that area.

Reuters contributed to this report.