In the new initiative, getting vaccinated is considered the "Key to NYC."

NYC Restaurant
Credit: Amir Hamja/Bloomberg via Getty Images

New York City will require those heading into indoor restaurants, entertainment venues, or fitness centers to show proof of vaccination, Mayor Bill de Blasio announced Tuesday.

The initiative, entitled "A Key to NYC" will require diners, fitness enthusiasts or anyone going to an indoor entertainment venue to show their CDC vaccination card or New York State's Excelsior Pass — similar to rules implemented in France and Italy. The vaccination requirement is currently encouraged and will be mandated starting Sept. 13, according to NBC New York.

The rule will also apply to employees in these venues.

"It's time for people to see vaccination as necessary to living a good and full and healthy life," de Blasio said during a press conference. "This is crucial because we know that this will encourage a lot more vaccination."

The mandate, which comes in the wake of the surging Delta variant, will not apply to outdoor dining.

Just over half of the New York City population has been vaccinated, according to city data, as de Blasio has incentivized residents to get the jab with $100.

As New York gears up to open safely after a year and a half of closures due to the pandemic, Broadway shows — which are slated to open gradually within the next few months — will require audiences to be vaccinated as well as wear a mask.

Elsewhere in the United States, Chicago has brought back its travel advisory list barring certain states from entering the city, and Los Angeles is once again requiring masks be worn indoors.