US Senate Majority Leader Chuck Schumer on Wednesday called on the feds to send 100 mobile COVID-19 testing sites to New York City and look into expanding locations on Long Island to prevent an explosion of Omicron cases from overwhelming the regions.

“We need these 100 mobile sites and we need FEMA to do it ASAP,” said Schumer (D-NY), who appeared at Mayor Bill de Blasio’s press briefing.

Schumer, in a letter to FEMA, insisted that it’s critical that the agency “provide the city with the necessary resources to help slow this spread.”

“I write today to ask for the Federal Emergency Management Agency’s (FEMA) assistance as we continue to fight the COVID-19 pandemic and the recent increase in cases due to the Omicron variant,” he wrote to FEMA Administrator Deanne Criswell.

“The spike in cases has brought upon an increased demand for testing that is sure to exceed the already robust testing infrastructure in New York City. In addition to supporting the City of New York’s request for an increased supply of at-home test kits, I ask that FEMA authorize the opening of 100 mobile test sites in New York City, and to also examine new sites on Long Island.”

So far, the feds have only committed to six Centers for Disease Control and Prevention-run mobile sites, the majority of which are slated for Queens, Schumer’s office said.

Speaking at the press briefing Wednesday, Schumer said that FEMA’s current plans to roll out six locations won’t cut it.

“That ain’t close to enough given the magnitude of the crisis and what we need,” Schumer said.

The first three mobile sites were announced Wednesday for locations in Queens, one of which began administering tests the same day near Travers Park in Jackson Heights, according to the city’s hospital system.

The two others will open Thursday near Queens Valley Playground in Flushing and by Helen Marshall Playground in East Elmhurst, officials said.

But Schumer said ramping up the Big Apple’s testing resources is necessary to tackle the Omicron variant.

“With more testing capabilities in the form of at-home kits and testing sites, the City can better gauge the trends of this variant and provide more accurate guidance and information to residents,” he wrote in his letter.

No further details were provided about where in the city the mobile sites were needed, as long lines have formed in recent days for testing throughout the five boroughs.

De Blasio on Wednesday said the Big Apple’s testing capacity was about 180,000 per day, about a quarter of which is administered through city-run sites.

New York City on Tuesday recorded its highest seven-day daily average of cases at nearly 9,500 infections, officials said.

Meanwhile, the Empire State on Tuesday logged 22,258 new infections, the third-highest day on record since the pandemic began, according to state officials.

Experts have urged New Yorkers to get COVID-19 vaccine booster shots, which preliminary studies have indicated significantly enhance protection against the Omicron variant — offering a $100 incentive to those who get the jab at city-run sites by Dec. 31. 

Of the 4.3 million eligible Big Apple residents, only 1.7 million — or nearly 40% — have received the additional dose, according to the Department of Health.

Dr. Mitch Katz, the chief of the city’s public hospital system, said Wednesday more research is needed to determine whether Omicron causes more severe disease in unvaccinated patients, who currently account for the “overwhelming” majority of their ICU hospitalizations.

Currently, there are 54 patients in ICU beds in city-run hospitals, down from a peak of 970 in March 2020 — though up from a low of about 20 weeks ago, he said.

But Katz that he’s concerned about the surge in cases causing staffing shortages.

“A lot of the preparation that I’m working is not because I’m worried about a deluge of sick patients, what I’m worried about is a large number of my own staff exposed to Omicron and therefore on 10-day isolations,” Katz said at the mayor’s press briefing.

“That’s already been happening and to the extent that I lose these people — and we have to lose these people in order for everybody’s protection — that’s the staffing problem that I’m worried about,” he added.