(NewsNation) — Travelers celebrating Father’s Day and Juneteenth faced the aftermath of a double holiday weekend with flight cancellations and delays piling up Monday for the fifth day in a row.

As of 12 a.m. ET Monday, airlines have already delayed more than 10,300 flights and canceled almost 2,000 flights, according to tracking service FlightAware.

On Sunday, airlines canceled 2,703 flights and delayed more than 19,000 flights, according to FlightAware. Over 900 of Sunday’s cancellations and 6,000 of the delays involved aircraft scheduled to fly to or from U.S. cities.

Airports with the most cancellations Sunday include Atlanta’s International Airport, New York’s John F. Kennedy International Airport, Boston Logan International Airport and Charlotte Douglas International Airport in North Carolina.

On Saturday, airlines canceled a total of 2,744 flights and delayed 18,171 flights. Of those, 859 canceled flights and 6,334 delayed flights were within, into or out of the U.S., according to FlightAware.

On Friday, TSA officers screened 2,438,784 people at airport security checkpoints nationwide, according to TSA spokesperson Lisa Farbstein.

In a tweet, Farbstein said, “It was the highest checkpoint volume since Nov. 28, 2021, which was the Sunday after Thanksgiving.” Farbstein attributed the busy travel day to the start of the “Juneteenth Holiday Weekend.”

American Airlines just announced it is ending service in three difference cities here in the U.S. because of that pilot shortage. Last week they announced they were stopping shortage in Toledo, Ohio. Today they announced they announced they were ending service in two New York cities: Ithaca and Islip. 

Transportation Secretary Pete Buttigieg met with airline leaders to quiz them about widespread flight disruptions after his own flight was canceled and he wound up driving from Washington to New York.

“That is happening to a lot of people, and that is exactly why we are paying close attention here to what can be done and how to make sure that the airlines are delivering,” Buttigieg told The Associated Press.

Buttigieg held a virtual meeting with airline CEOs to go over steps the airlines are taking to operate smoothly over the July 4 holiday and the rest of the summer, and to improve accommodation of passengers who get stranded when flights are canceled.

Buttigieg said he is pushing the airlines to stress-test their summer schedules to ensure they can operate all their planned flights with the employees they have, and to add customer-service workers.

Buttigieg said his department could take enforcement actions against airlines that fail to live up to consumer-protection standards. But first, he said, he wants to see whether there are major flight disruptions over the July Fourth holiday weekend and the rest of the summer.

Airlines canceled more than 1,500 flights in the U.S. on Thursday, one of the worst days yet for travel as the peak summer vacation season heats up.

The airlines blame bad weather and the Federal Aviation Administration, an arm of the Transportation Department that manages the nation’s airspace, for the recent disruptions. In a letter to the senators, the head of trade group Airlines for America Nicholas Calio ticked off a long list of FAA delays and staffing problems over the holiday weekend.

In an email to NewsNation, a spokesperson from the FAA wrote: “Airlines have been unable to bounce back when they encounter severe weather, as we saw this weekend.”

But some pilots are telling a different story, blaming airlines, instead, for the travel troubles.

“The whole world’s watching and they’re stumbling left and right,” Captain Dennis Tajer told “Rush Hour” on Monday.

Tajer is the communications committee chairman for the Allied Pilots Association.

“Shame on management for building schedules that our traveling public depends on to get them on vacation that’s right up to the edge — there’s no buffer —they go right to the maximum so when anything happens, it falls apart and has to be rebuilt,” Tajer said.

Airlines have also acknowledged staffing shortages as travel roared back faster than expected from pandemic lows. Airlines are scrambling to hire pilots and other workers to replace employees whom they encouraged to quit when the pandemic hit.

Captain Laura Einsetler, an airline pilot with more than 30 years of experience, told NewsNation, “This is a response to rebounding from the pandemic. So, with every everything — the layoffs that we had, the downsizing that we had — right now, we’re just having to rebound from all of that.”

Last week, pilots for Delta Air Lines wrote an open letter to customers, saying the large number of recent flight delays, cancellations and cuts were “unacceptable” and they were “flying a record amount of overtime to help you get to your destination.”

“As pilots, we’re doing everything we can to fly on our days off, cancel our vacation so that we can fly everyone else for their vacations,” Einsetler said, “You know, there’s so many things that we’re trying to do to just work with the airlines for the passengers to get everybody where they need to go.”

As the travel demand increases amid airline staffing shortages, pilots are being pushed to their limits trying to get travelers to their destinations.

So far in June, more than 2.2 million travelers a day on average have gone through security checkpoints at U.S. airports. That’s up 22% from a year ago, although still down 13% from the same period before the pandemic.

There are some things travelers can do to mitigate delays, however. In an interview with NewsNation, travel expert Brett Snyder said passengers should build in more time between connections, and book nonstop flights whenever possible.

“The airspace in the Northeast tends to be the one that gets the most crowded, and then if the weather hits in the Northeast it becomes a real problem,” Snyder said. “If you’re connecting somewhere – say you’re going to Europe – and you can avoid connecting in the Northeast, that might be a helpful plan.”

The Associated Press and the Hill contributed to this report.