Following the outbreak of the Delta strain of COVID-19, New York City has altered its virus policy. Mayor Bill De Blasio announced Tuesday that starting in September, those wishing to survey indoors venues such as city gyms, restaurants, and indoor entertainment centers will be required to present a certificate of vaccination in order to enter the facility.

New York is set to become the first state in the union to introduce the measure, forcing anyone seeking to spend time indoors to prove they have been vaccinated.

"If you want to take part in everyday social life, go get vaccinated. It's about time. If we want to stop the Delta variant, now is the time to do it," said the mayor.

De Blasio said the mandate, known as the Key to NYC Pass, would encourage increased immunizations of local citizens.

"I'll be clear: Do you want to enjoy all the wonderful things this summer in New York? Go get vaccinated," De Blasio wrote on his Twitter account.

"When you hear those words, 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,” de Blasio said of the new measure.

Bill Neidhard, a spokesman for the mayor, added that "New York is going to lead the world in creating safe and secure public spaces."

De Blasio is considered to have taken a tough stance in the fight against the Coronavirus, and at the end of July ordered all health system workers to be vaccinated or undergo weekly testing, and then extended the rules to all city employees.

New York officials told local media that the plan came as a result of various European countries weighing the idea.

In an interview with MSNBC last week, de Bellasio said: "We need to shake people at this point and tell them 'enough is enough.'"

Video: Reuters