Mayor de Blasio balked at the idea of reinstating an indoor face mask mandate in the city on Monday even though COVID-19 infections are ticking back up. Instead, he called for more vaccination efforts throughout the five boroughs.

“Masks have value, unquestionably, but masks are not going at the root of the problem. Vaccination is,” the mayor said during a live-streamed press briefing. “So we do not intend a mask mandate. We do intend to double down on vaccination.”

Over the weekend, some local public health experts and lawmakers began calling for a resumption of indoor mask wearing for all New Yorkers — regardless of vaccination status — citing a slow but steady rise in coronavirus infections driven by the Delta variant.

But de Blasio said in his briefing that it would be “a disservice” to heed those calls and argued all focus should instead be on boosting vaccinations.

“Let’s address the problem by getting more people vaccinated and going right at it, and knocking down this variant,” he said from City Hall. “You know, a mask doesn’t arrest the progress of the variant — vaccination does. So we’re gonna go where the real impact is. That’s the bottom line.”

Democratic Manhattan Councilmember Mark Levine, who chairs the City Council’s Health Committee, took issue with de Blasio’s argument and said an indoor face mask mandate could safeguard New York against a major COVID-19 outbreak while the vaccination campaign continues.

“We can’t ignore what’s happening here,” Levine wrote on Twitter along with a link to Health Department data showing that the city’s COVID-19 case growth has been exponentially increasing in just the past two weeks.

Public Advocate Jumanee Williams echoed Levine’s sentiment and argued a resumption of indoor mask-wearing would be a small price to pay.

“Certain communities still have low vaccination rates,” Williams tweeted. “Indoor masks (especially with no ventilation) should be mandated again. We waited before, and people died.”

At the moment, New York City only requires fully vaccinated individuals to wear masks in hospitals and schools as well as on public transportation and in congregate settings like homeless shelters.

Meantime, the city’s test positivity rate — which provides a snapshot of how fast the virus is spreading — has been on the upswing for weeks, with the seven-day rolling average reaching 1.69% on Monday, Health Department data shows. A majority of new infections are traced to the Delta variant, a highly contagious version of the virus that first originated in India.

By contrast, 41.9% of New York City’s population has yet to get vaccinated, according to the Health Department, giving the virus room to spread.

Dr. David Chokshi, de Blasio’s Health Commissioner, noted in the briefing that unvaccinated individuals are still required to wear masks in all public settings where social distancing is not possible.

But Levine said that distinction is nearly impossible to enforce, especially in settings like grocery stores, bars and restaurants, where patrons and customers generally aren’t screened.

“The rule of thumb should be: in indoor settings where there’s no screening for vax/test status, everyone should wear a mask. This must include vax’d because there’s a very small chance they can still receive/transmit, and because we need mask solidarity. Otherwise, it doesn’t work,” he wrote on Twitter.

Despite a stated focus on jacking up vaccination rates, the de Blasio administration also does not appear to have any additional major plans of action in the works.

Asked about the fact the nearly one-third of city hospital staff remains unvaccinated, de Blasio simply said he’s “very hopeful” that will soon change and stopped short of supporting a vaccine mandate for that demographic.

“Those conversations are going on right now,” he added.

De Blasio was more adamant about the Central Park concert he has planned for next month to celebrate the city’s “comeback” from the pandemic.

“You’ve heard some of the initial acts. They’re amazing,” de Blasio said, referring to his previous announcement that Bruce Springsteen, Paul Simon and Jennifer Hudson are among the Aug. 21 concert’s headliners. “There’s a lot more coming, that’s all I can say. It’s going to be one of the most memorable concerts in the history of New York City.”

Though concern is mounting about the Delta variant, the city’s current positivity rate is far lower than the 6% reported in March, when the second wave of the virus began to roll back.

Hospitalization and death rates also remain low. Three New Yorkers died from COVID-19 on Sunday, according to the State Department of Health.

But some New York legislators believe officials must take a hawkish stance against any sign of a coronavirus resurgence.

“NY’s leadership did not act quickly enough in the beginning of this pandemic and we suffered losses,” said Democratic Queens Assemblywoman Jessica González-Rojas.

It’s not just New York City that is seeing a Delta-driven surge in coronavirus infections.

Statewide, the coronavirus test positivity rate is also going up, with the seven-day rolling average count clinching 1.26% Monday, according to State Department of Health data.

Outside of New York, the Delta variant is wreaking even more havoc, with states like Missouri reporting skyrocketing infection, hospitalization and death rates.