Travel and hospitality CEOs are stepping up pressure on the Biden administration to scrap a requirement that anyone flying into the U.S. present a a negative Covid-19 test before departure, saying the rule is discouraging visitors and hurting the country’s tourism industry.

The push comes after the United Kingdom, Italy, Greece and others have lifted similar requirements as pandemic restrictions ease around the world.

In the U.S., health officials still require travelers flying into the country to provide proof of a negative Covid-19 test, regardless of their vaccination status or citizenship. People can also present proof that they recovered from Covid. Other countries including South Korea and Japan also require travelers to present a negative Covid test.

“Requiring pre-departure testing creates uncertainty for travelers, one more hurdle that may lead them to choose a destination with less friction,” Marriott CEO Tony Capuano said in a statement to CNBC. “The U.S. will miss out if we don’t eliminate those unnecessary barriers.”

Nearly 40 U.S. mayors including from San Francisco and Miami also sent a letter this week to Dr. Ashish Jha, the White House Covid-19 coordinator, urging him to lift the requirement. The letter said American cities are still struggling to regain international visitors.

Travel industry executives also met with Jha last week, but say they didn’t get a timeline for when the requirement might end.

“They are unable to cite when pre-departure testing will be lifted,” Tori Barnes, president of the U.S. Travel Association, told CNBC after the meeting.

The White House did not return request for comment.

“Pre-departure testing is holding international travelers back from bookings a trip to the U.S.,” said Jon Bortz, CEO of Pebblebrook Hotel Trust, which owns 54 hotels around the country.

Glenn Fogel, CEO of the world’s largest online travel operator, Booking Holdings, said the test requirement is pushing people to visit other countries. In other cases, he noted people just find ways around the requirement.

“We also see instances of people simply avoiding the restriction by flying into Canada or Mexico and driving across the board,” Fogel said in a statement.

In a note to investors Wednesday, Morgan Stanley analyst Jamie Rollo wrote that the testing requirement is becoming especially concerning for cruise travelers, who worry about being stuck on a ship testing positive.

Keith Barr, CEO of InterContinental Hotels Group, expressed frustration with the country’s testing requirement on CNBC’s “Closing Bell” Tuesday.

“It’s out of step with the rest of the world,” he said.