New York City Mayor Bill de Blasio has announced an aggressive new strategy to get people vaccinated against Covid-19, confirming that activities like indoor dining and attending gyms will soon be exclusively for the inoculated.

“The only way to patronize these establishments indoors will be if you’re vaccinated,” the mayor announced on Tuesday, citing concerns over the fast-spreading Delta variant.

The requirement will be phased in through August and September and will require patrons entering certain establishments to have had at least one dose of a Covid-19 vaccine. This can be proven through either a vaccination card or vaccination apps.

De Blasio did not get into specifics about how the mandate would be enforced. He said the rules will go into effect on August 16, but inspections won’t be carried out until September 13.

The mayor also previously announced that all city employees will soon be required to be vaccinated by September, or they will have to subject themselves to weekly testing.

Around 66% of New York adults have been vaccinated already – one of the highest rates in the country – but the state has been one of the hardest-hit by Covid-19.

Numerous states are seeing rises in Covid-19 cases as they pull back lockdown restrictions, leading some counties to reinforce masking requirements. Cities like Los Angeles and Las Vegas, for instance, have brought back mask mandates to curb the rise in new cases.

De Blasio’s program, known as the ‘Key to NYC Pass’, will send the message “clearly” that vaccinations are the way to end the pandemic, according to the mayor. 

“When you hear those words,” de Blasio said of the Key to NYC Pass, “I want you to imagine the notion that, because someone’s vaccinated, they can do all the amazing things that are available in this city.”