Airlines canceled more than 2,200 U.S. flights on Sunday and Transportation Secretary Sean Duffy warned air travel will fall to a "trickle" in the run-up to the Thanksgiving holiday as air traffic control staffing shortages surge during the federal shutdown.

Major airlines were dealing with a third day of government-mandated flight cuts after thousands of delays and cancellations snarled traffic on Saturday. The shutdown, which has reached a record 40 days, has led to shortages of air traffic controllers who, like other federal employees, have not been paid for weeks. "It's only going to get worse... the two weeks before Thanksgiving, you're going to see air travel be reduced to a trickle," Duffy said on CNN's "State of the Union" program.

Millions of people usually travel in the run-up

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