Transportation Secretary Pete Buttigieg sent a letter Friday to several U.S. airlines calling for a resolution to the surge in cancellations and delays.

The letter to 10 U.S.-based airlines comes amid a sharp increase in demand for air travel after the height of the pandemic in 2020.

"The level of disruption Americans have experienced this summer is unacceptable. In the first six months of 2022, roughly 24% of the domestic flights of U.S. airlines have been delayed and 3.2% have been canceled," Buttigieg said in the letter.

The letter noted that new rules can be implemented if the situation isn't resolved. Buttigieg cited how flight disruptions have meant travelers have "missed birthday parties, graduations, time with loved ones and important meetings."

"Americans expect when they purchase an airline ticket, they will arrive at their destination safely, reliably, and affordably," Buttigieg said.

The Department of Transportation is expected to launch a website before Labor Day weekend that will inform travelers about airlines' cancellation, delay and refund policies.

"When passengers do experience cancelations and delays, they deserve clear and transparent information on the services that your airline will provide, to address the expenses and inconveniences resulting from these disruptions," Buttigieg said.

Airlines have blamed staff shortages, specifically a lack of pilots, for the delays and cancelations. U.S. airlines issued a total of $21.8 billion in cash refunds to travelers in 2021 and 2021, according to Airlines for America, a Washington, D.C.-based American trade association and lobbying group.

The move by the Department of Transportation comes after Sen. Bernie Sanders, I-Vt., sent a letter to Buttigieg in June that addressed "skyrocketing flight delays, cancellations, and outrageously high prices and hidden fees." Sanders called it "unacceptable" that "ticket prices have skyrocketed by 38% over the past year, while airline delays have increased by 50%."