Despite a recent push from dozens of lawmakers for the United States to add a vaccination requirement on domestic flights, the prospect of a federal mandate is looking slim.

During an interview Sunday on NBC’s “Meet the Press,” Transportation Secretary Pete Buttigieg said strategies other than a vaccine mandate — such as requiring masks and vaccinating travel industry workers — are “highly effective.” The Transportation Security Administration has extended the federal mask mandate for planes, airports, trains and other mass transportation through Jan. 18, 2022.

Host Chuck Todd pressed Buttigieg on the issue, questioning whether he was nervous about putting a policy in place that was politically divisive. The back-and-forth came at the beginning of the busy Thanksgiving holiday season in which TSA expects to screen about 20 million people. At the same time, new daily reported coronavirus cases in the United States have risen 12 percent over the past week, according to data from The Washington Post.

“If we’re trying to get to the end of this pandemic, continuing to have sort of loopholes to avoid a vaccine seems to elongate this pandemic,” Todd said.

Sidestepping the political question, Buttigieg said current practices are working.

“Between the masking and the other mitigations, we’re very confident in the safety of air travel and travel generally in this country,” he said.

As mask mandates lift, we're going to have to decide whether or not to wear a mask indoors. (Monica Rodman/The Washington Post)

After being closed to travel from much of the world since March 2020, the United States reopened to foreign travelers earlier this month, as long as they are vaccinated and test negative. Buttigieg said international visitors need to show proof of vaccination “because different countries have different standards.”

In a letter to Biden earlier this month, lawmakers lauded the vaccine mandate for international travelers, which had just gone into effect. They called a domestic version — which would require proof of full vaccination or a recent negative test — “necessary and long overdue.”

“Applying similar strategies to domestic air travel would ensure Americans can travel safely to see their loved ones during the holidays while also limiting household introduction and spread of covid-19 from visiting family and friends,” the letter said.

Among the 36 Democrats who signed: Sen. Dianne Feinstein, of California, and Rep. Don Beyer, of Virginia. Both have filed legislation seeking similar requirements.

Airline executives have said a domestic vaccine mandate for flying would be “logistically impractical” and “incredibly cumbersome.”

Anthony S. Fauci, Biden’s chief medical adviser, has said he would support a vaccine mandate to fly domestically if the president wanted to implement one. But last month, he told CNN he didn’t see it happening anytime soon.

“On the table is the issue of mandates for vaccine,” he said. “It’s always discussable, we always wind up discussing it, but right now I don’t see that immediately.”