New York City will soon start requiring people to show proof of coronavirus vaccinations for indoor activities such as dining and working out at gyms, Mayor Bill de Blasio announced Tuesday, making it the first major U.S. city to implement such a policy.

The new requirement takes effect Aug. 16 and will include restaurants, indoor fitness centers and entertainment facilities. Workers and customers will have to show they have received at least one vaccine dose.

The mayor said the policy is necessary to combat the delta variant of the virus sweeping across the country.

“It’s time for people to see the vaccine as literally necessary for living a good and full and healthy life,” said de Blasio (D) at a morning news conference. “This is crucial because we know this will encourage a lot more vaccination. We’ve seen it already.”

Here are some significant developments:

New York’s requirement is similar to programs recently adopted in France, Germany and Italy, and represents one of the most aggressive moves to date by a major U.S. city to control the surge of infections. The hyper-transmissible delta variant is driving up infections in every state, creating a new sense of urgency to ramp up immunizations before the latest wave of infections and hospitalizations gets worse.

Some cities have mandated vaccines for city employees, but few have broached the idea of requiring residents to show proof that they’ve received the shots to participate in everyday activities. Such a move would be banned in some states, including Texas and Arkansas, where lawmakers have passed prohibitions on vaccine mandates. In Washington, House Minority Leader Kevin McCarthy (R-Calif.) on Tuesday decried New York’s requirement as an “abuse of power.”

New York officials acknowledged that the program would face opposition but said it was critical to stop the city’s rapid rise in cases.

“Our choice is to act now or face more difficult options down the road,” New York city council member Mark Levine, a Democrat who chairs the health committee, said in Tuesday’s news conference. “This is not an easy policy, it’s not a policy without controversy, but that has defined every difficult decision we’ve had to make in this crisis.”

Some of New York’s private businesses, including Broadway theaters, have already started mandating vaccinations for patrons and workers, paving the way for the citywide requirements, de Blasio said. New York has also already implemented a vaccine mandate for city workers. About 60 percent of New York residents of all ages have received at least one vaccine dose, according to city data, including roughly 66 percent of New York City adults who are fully vaccinated.

“Climbing this ladder is giving us more and more ability to fight back the delta variant,” de Blasio said. “By fighting the delta variant, we will continue our recovery, and we will ultimately beat covid.”

City officials will spend the next two weeks listening to feedback from the business community before unveiling the final details of the policy, de Blasio said. They’ll also spend about a month on a public education campaign to ensure business owners and residents understand the new approach. Inspections and enforcement will begin in mid-September, de Blasio said.

“The goal here is to convince everyone that this is the time,” he said. “If we’re going to stop the delta variant, the time is now.”

The NYC Hospitality Alliance, a trade group representing more than 24,000 restaurants and nightlife establishments, called the policy “far from ideal” but said it could ultimately benefit the city’s businesses.

“Mandating vaccine requirements for restaurant and bar employees and customers to work and dine indoors is a very difficult step,” Andrew Rigie, the group’s executive director, said in a statement. But it “may prove an essential move to protecting public health and ensuring that New York City does not revert to restrictions and shut down orders that would again absolutely devastate small businesses that have not yet recovered from the pandemic.”

As cities try to boost vaccinations within their borders, the Biden administration on Tuesday announced what it called a “major milestone” in its global immunization campaign, reporting that the United States had shipped more than 110 million doses of coronavirus vaccine to more than 60 countries.

“The United States will be an arsenal of vaccines for the world and is acting with the same urgency to combat the virus abroad as here at home,” the statement said.

President Biden pledged to donate at least 80 million vaccine doses from the U.S. supply throughout the world by the end of June. Albeit delayed, the distribution announced Tuesday fulfills that promise and “cements the United States as the global leader in COVID-19 vaccine donations,” the White House said.

The majority of the vaccine was made in the United States, according to the White House, and shipped through Covax, an initiative backed by the World Health Organization to distribute vaccine doses equitably. Bangladesh, Colombia, Indonesia and the Philippines — all hit hard with coronavirus cases — are among the countries receiving the highest number of donated vaccine doses.

The distributions fall far short of the 11 billion doses that WHO Director General Tedros Adhanom Ghebreyesus has previously said would be needed to “truly end the pandemic” by vaccinating at least 70 percent of the world’s population by next year.

Covax, as of the end of July, had shipped more than 153 million coronavirus vaccine doses to countries, humanitarian agencies and other entities participating in the program, according to GAVI, the global vaccine alliance behind Covax. However, the program has faced criticism for the sluggish delivery of vaccine after pledges.

Low- and middle-income countries have accused wealthy nations of snapping up the global vaccine supply, and the WHO has warned of future variants emerging from countries with large unvaccinated populations. The United States will also begin shipping 500 million Pfizer-BioNTech doses to 100 low-income countries at the end of the month, the White House said.

Domestically, Democratic governors and local leaders across the country are splitting over how to combat rising cases fueled by the more contagious delta variant. Some are mandating masks, while others say boosting shots is the only way forward.

In Louisiana, where caseloads are overwhelming some hospitals, Gov. John Bel Edwards (D) reinstated an indoor mask mandate for people 5 and older Monday evening, saying the vaccination rate was “insufficient.”

“Mask-wearing when you are in public is one way to greatly lower your risk of spreading or catching covid,” Edwards said in a statement. “Being vaccinated against covid-19 is another.”

Other Democratic leaders are calling mask mandates a nonstarter, instead putting all their focus on encouraging people to get vaccinations as a shield against rising cases.

“Mask-wearing is not a substitute for vaccination,” de Blasio said Monday, rejecting the idea of a mandate. New York City workers, including teachers and police officers, are required to be vaccinated by mid-September or be tested weekly for the coronavirus. Gov. Andrew M. Cuomo (D) on Monday urged private businesses to allow only vaccinated patrons.

Louisiana is battling the delta variant with one of the lowest vaccination rates in the country: just 37 percent of the state’s population is fully vaccinated. Unvaccinated people account for 90 percent of hospitalizations in Louisiana, according to state data.

Vaccine hesitancy — fueled by misinformation online and a lack of trust in the medical establishment in some communities of color because of the country’s history of medical experiments on minorities — has hampered the inoculation effort in Louisiana. Though the state has a Democratic governor, it is still largely conservative, a bloc more likely to spurn vaccinations.

Louisiana is averaging more than 4,600 cases per day — its highest level yet during the pandemic, surpassing the spikes over the winter and last summer, before vaccines were available. More than 11,000 new cases were reported in Louisiana on Monday, by far the state’s largest daily total of the pandemic.

Many Republican governors in recent weeks have also said that mask mandates will not make a comeback in their states. Texas Gov. Greg Abbott (R) issued an executive order banning mask mandates, citing vaccination as the most effective defense against the virus.

On Capitol Hill, Sen. Lindsey O. Graham (R-S.C.) said Monday that he tested positive for the coronavirus after being vaccinated in December, making him the first known senator with a breakthrough infection from the virus.

Graham tweeted that he would isolate for 10 days, but his case raised concerns after he attended several recent GOP and Senate events without wearing a mask.

Some U.S. businesses are also returning to mask mandates. McDonald’s said Monday that it would require its customers and staff to wear face coverings in areas with high or substantial transmission, regardless of vaccination status. Walmart, Home Depot and Target also have put in place mask mandates for workers and strong recommendations for customers in U.S. counties deemed at high risk of coronavirus transmission.

Tech giants Facebook and Google recently mandated vaccinations for all employees in U.S. offices.

Hannah Knowles contributed to this report.