NEW YORK, United States --Clutching vaccination cards and personalized QR codes, New Yorkers showed proof of inoculation against COVID-19 to enter restaurants, gyms and movie theaters Tuesday as America's first city-wide vaccine mandate got underway.

The policy -- announced by Democratic Mayor Bill de Blasio earlier this month -- comes as the United States steps up vaccine requirements to help fight the hyper-contagious Delta variant.

"It's a no-brainer," said 33-year-old Casey Shane at a fitness center in Manhattan, where he presented his state-issued vaccine "pass" on his phone before working out.

"If you want to do the things that you love to do then this is what you need to do, not only to keep yourself safe but your fellow community members safe too," added the actor.

New York is the first city in the United States to demand evidence of at least one vaccine shot to access indoor dining, bars and nightclubs, entertainment venues and museums.

Establishments have until September 13 to comply, after which they face $1,000 fines. Children under 12 are exempt because they are not currently eligible for vaccines.

"This is the way we bring back our city fully," de Blasio told reporters Tuesday.

With enforcement a month away, the mandate appeared to start slowly but many businesses said they were on board.

A sign on the door of a New York Sports Club gym on the Upper West Side said it would make "no exceptions" for unvaccinated patrons, guests and staff. "NO PROOF, NO ENTRY," screamed the notice.

"Our members are regulars. They know, and they just do it," said manager Michelle Weed. "For the most part, we haven't had to remove anybody."

- Texas ban -

Many New Yorkers remain traumatized by the pandemic which has killed more than 33,000 residents since it swept the city of more than eight million last spring.

Some 74 percent of adults have received at least one vaccine dose, official figures show.

Seventeen-year-old Thisbe said she felt safer watching a movie knowing everyone in the audience was vaccinated like her.

"Unvaccinated people cannot come in, but it's their choice," she said outside a theater in Greenwich Village.

Not everybody spoken to by AFP supported New York's mandate, though, while some business owners fear it could turn people off.

"It's nonsense," said 47-year-old Samuel, who is vaccinated but believes it should be a personal choice.

"It's un-American. I don't like being forced to do something," he added, while eating lunch at an Irish pub in Manhattan.

Other cities have followed New York's lead, including San Francisco, which will demand proof of full vaccination from August 20.

At the opposite end of the spectrum are cities in Texas, which have been banned by their Republican governor from mandating vaccines.

Alton Thibodeaux, 74, and his wife Jean eagerly held their paper vaccination cards as they waited to have lunch at a French restaurant in New York.

They were visiting from Louisiana, which has one of America's lowest vaccine rates, and would like to see more cities adopt mandates.

"I think that's the only way we're ever gonna get rid of it," said Thibodeaux, who is retired.

"It shouldn't be a political issue or anything like that, just get it and get this over with and everything will be fine."