The cancellations came less than three weeks after airlines kicked off the summer travel season by canceling about 2,800 flights over a five-day period around the Memorial Day holiday weekend.

And they came as airline CEOs held a virtual meeting with Transportation Secretary Pete Buttigieg – a sign of the Biden administration’s concern over the prospect of blocked airports and disgruntled travelers this summer. .

“I’m letting them know this is a time when we really rely on them to reliably deliver to the traveling public,” Buttigieg told NBC News.

During the meeting, which was held via videoconference, Buttigieg asked the CEOs to outline the steps they are taking to operate smoothly during the July 4 holiday and the rest of the summer, according to a person familiar with the matter. call but not authorized to discuss it publicly. .

Buttigieg also pushed airlines to consider whether they could manage the schedules they published and to improve customer service, the person said.

Airlines for America business group chief Nicholas Calio said in a statement that industry officials appreciated the opportunity to speak with Buttigieg and “discuss our shared commitment to prioritizing safety and the safety of all travellers”.

Airlines are grappling with shortages of workers, especially pilots, which are hampering their ability to operate all of their scheduled flights. Pilot unions at Delta, American and Southwest said their airlines were too slow to replace pilots who retired or took furlough early in the pandemic.

Two Senate Democrats said this month that the holiday weekend performance “raises questions about airline decision-making.” Richard Blumenthal of Connecticut and Edward Markey of Massachusetts said delays and cancellations “occur so frequently that they become an almost expected part of travel.”

The airlines blame bad weather and the Federal Aviation Administration, a branch of the Department of Transportation that manages the nation’s airspace. In a letter to senators, Calio ticked off a long list of FAA delays and personnel issues over the holiday weekend.

Airlines jousted with the FAA this spring over delays in Florida, where air travel has recovered faster than in many other parts of the country. After meeting with airline officials in May, the FAA agreed to increase staffing at an air traffic control center near Jacksonville and make other changes.

Concerns over flight issues come as the number of air travelers to the United States exceeds 2.2 million a day. That’s still about 300,000 fewer per day than in mid-June 2019, but crowds will grow over the next few weeks and will almost certainly break the pandemic-era record set on the Sunday after Thanksgiving last year.

Bottlenecks could arise at airports of entry where travelers enter the United States. Last weekend, the Biden administration dropped a 16-month requirement that people had to test negative for COVID-19 before boarding a flight to the United States. The move is expected to boost international travel – United Airlines said on Monday it had seen an immediate increase in overseas searches. flights.

Another threat: The FAA is urging airlines to quickly upgrade equipment that could be vulnerable to radio interference from the new wireless service. The agency’s acting administrator, Billy Nolen, told airlines on Wednesday that Verizon and AT&T plan to turn on hundreds of C-band 5G transmitters near airports on July 5.

Grim forecasts of fallout from the initial C-band service from mobile phone companies did not materialize earlier this year. Still, Nolen said the FAA can’t promise there won’t be problems with some planes. He said industry officials have found a way to retrofit many planes with problematic equipment by the end of the year and more in 2023.

Shares of the six largest U.S. airlines fell between 6% and 9% on Thursday as jitters about the economy dragged the broader market down.