By CBS13 Staff

SACRAMENTO (CBS13) — Thousands of flights were delayed or canceled across the United States over the weekend, and federal officials say it could be weeks before the situation improves.

While there was only one cancellation and a handful of delays Monday morning at Sacramento International Airport, the situation was different at other major airports across the country. Many travelers saw their plans upended, just as the summer travel season gets underway.

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According to the Transportation Security Administration, Friday was the busiest air travel day so far this year, with 2.5 million people passing through security checkpoints. Yet, since Thursday, there’ve been more than 19,000 flight cancellations and delays across the country.

Airlines say the uptick in travelers, combined with a pilot shortage and severe weather, led to the cancellations over the last few days. Delta and American Airlines say that the cancellations have reduced their schedules by 7% and 5%, respectively.

“Canceling a flight is always our last resort,” said Delta Air Lines, in a statement, “and we sincerely apologize to customers for the inconvenience to their travel plans.”

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U.S. Secretary of Transportation Pete Buttigieg met with airline executives last week in the hopes of resolving some of these travel issues ahead of July 1, which is expected to be the busiest travel day of the summer.

These travel headaches come as airlines are still struggling to adjust amid the ongoing COVID-19 pandemic.

What happens if your flight is canceled?

If an airline cancels your flight, they are required to rebook you on the next available flight with space.

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However, if that is not available, the airline must provide a refund, even if your ticket was “nonrefundable.”