Mask requirements on airplanes and other transit remain in place because workers “don’t have a choice” about being there, Transportation Secretary Pete Buttigieg argued on Sunday — as air travel boomed for Memorial Day weekend.

“Some of the differences have to do with the physical space, some of them have to do with it being a workplace where, in some of these transit and travel situations, people don’t have a choice,” Buttigieg told Martha Raddatz on ABC’s “This Week,” when asked why vaccinated Americans can go mask-free in restaurants and gyms but not planes.

Public health officials said earlier this month that vaccinated Americans could go unmasked indoors — with some notable exceptions, including airplanes and transit.

The TSA’s mask mandate is slated to be in effect until at least Sept. 13.

“Of course the decisions will continue to be on the part of public health authorities and driven by public health considerations,” Buttigieg added, “but just remember that the flight crews and other workers you encounter, they’re doing their job, they’re following regulations, and they’re there to keep you safe.”

“It is absolutely unacceptable to ever mistreat a transportation worker and of course, there’s very serious fines and enforcement around that,” he said.

“It’s a matter of safety, but it’s also a matter of respect.”

Buttigieg made the Sunday TV news show rounds as Americans took to the skies in ever-growing numbers for the Memorial Day weekend.

Friday and Saturday saw over 3.5 million people pass through American airport security, according to TSA figures — compared to around 600,000 over the same two-day period last year.

Air travel sits at around 76 percent pre-pandemic levels, the TSA said.