The world famous Times Square crystal ball is illuminated and elevated for a final test, a day ahead of the New Year's Eve celebrations at Time Square, on December 30, 2020, in New York City.
CNN  — 

New York City’s mayor is hopeful that the annual New Year’s Eve Times Square celebration will happen as planned amid a Covid-19 case surge, though he’s talking with health leaders and sponsors about whether to add safety measures, he said Wednesday.

“We’re looking to add additional measures to make it even safer,” Mayor Bill de Blasio told CNN’s John Berman.

De Blasio didn’t go into details. The outdoor event already is restricted to people who can show proof of vaccination.

“So, we’re still in discussion. The goal, of course, is to keep it going because it’s such an important event for New Yorkers and for the whole world,” de Blasio said on CNN’s “New Day.”

“But if we’re able to figure out the right formula to keep people safe, that’s what we’re working on right now,” he said.

“I’m hopeful. We’ve got more work to do, and jury’s not back yet, but I’m hopeful.”

Earlier this week, de Blasio said city officials were reviewing plans for the event in light of a Covid-19 case surge and the spread of the highly transmissible Omicron variant of the coronavirus. On Tuesday, he said he was hopeful that the event could go on as planned.

In November, de Blasio announced the return of a “big, strong, full strength” in-person New Year’s Eve celebration in Times Square this year following its virtual event last year due to pandemic concerns.

The usual countdown and famous ball drop happened last year, but no crowds were allowed on the streets. Other cities also held scaled-back celebrations.

“We want to welcome those hundreds of thousands of folks – but everyone needs to be vaccinated,” de Blasio cautioned at a news conference November 16. “All you need to do is have proof of vaccination and a valid photo ID and you are in.”

Those who cannot be vaccinated must show proof of negative PCR test within 72 hours and wear a mask.

The pandemic has entered a new phase as the Omicron variant spreads, prompting businesses and attractions to step up restrictions or cancel events.

Multiple shows on Broadway have gone dark, the Radio City Rockettes’ Christmas Spectacular has been closed for the rest of the season, and “Saturday Night Live” aired December 18 without a live audience.

Several countries around the world are again imposing restrictions on travel and large gatherings to stem the spread of the virus, including China, which is working to keep any new outbreaks contained ahead of the Winter Olympics in February.

Fully vaccinated travelers from all but eight nations are allowed to come to New York City, and domestic visitors are currently welcome under some restrictions, including wearing masks in indoor public places.

CNN’s Jason Hanna contributed to this report.