New York City Mayor Bill de Blasio on Tuesday announced new rules that will require proof of vaccination in certain public spaces, expected to go into effect by the end of the month.

It's part of an effort to keep New Yorkers safe as the delta variant pushes coronavirus infections higher. The first-in-the-nation mandate will require anyone who wants to dine at a restaurant, attend an indoor concert or work out at a gym indoors to show proof of vaccination.

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For the NYC Hospitality Alliance, it marks a step to prevent restrictions.

"That could help stop us from the city or state or federal government, implementing even stricter restrictions that we know will put even more burden on restaurants that are so far from even recording yet." says Andrew Rigie, the alliance's executive director.

De Blasio says the initiative is the "key to NYC Pass" that will require at least one dose of the vaccination for workers and customers. The new program is expected to be put in place by Aug. 16, with inspections and full enforcement beginning the following month, on Sept. 13.

But some are voicing concerns about the new mandate. Rep. Nicole Malliotakis (11th District) says she believes the mayor is demonstrating "an extraordinary level of government overreach."

The plan comes as the city continues to plead with New Yorkers to get the COVID-19 vaccine. The mayor recently announced a $100 cash incentive. He said today that 5 million New Yorkers have received their first vaccine dose so far -- and over 11,000 New Yorkers have now claimed that incentive.