New York Gov. Kathy Hochul declared a state of emergency in response to a winter coronavirus spike and the threat of the newly detected omicron variant on Friday, making her state one of the first in the country to impose measures against the mutation that was recently sequenced in southern Africa. 

As part of the emergency, the state's Health Department will be allowed to protect hospital capacity by limiting nonessential and non-urgent care until at least Jan. 15. Hospitals with less than 10% staffed bed capacity, or those designated by the state, will be authorized to screen patients and restrict admissions to keep beds open for the most urgent cases.

The Centers for Disease Control and Prevention said Friday that omicron had not yet been detected in the United States, though Hochul said of the variant: "it's coming."

She also urged New Yorkers to mask up in indoor public venues, get tested when appropriate and to stay home when ill. She also reminded residents to get vaccinated or boosted against the coronavirus.

New York has fully vaccinated slightly over two thirds of its residents, Washington Post figures show. Close to 80% of the state's 20 million residents have received at least one dose, according to the governor's office. But Hochul noted in her executive order that the virus is transmitting at rates not seen since April 2020, when New York was at the center of the global pandemic.

"This is a concerning development that we must watch extremely closely, and be prepared to address as a city, state and country," said New York City mayor-elect Eric Adams of omicron in a statement. "Our health officials must ... have response options available should it prove to be significantly more virulent."

Hochul's order came on the same day that the Biden administration said it would restrict flights from southern Africa.

The nation's top infectious-disease experts, including Anthony Fauci, urged caution even as they acknowledged that there were many unknowns about omicron, which the World Health Organization designated a variant of concern on Friday. U.S. health officials are in touch with their South African counterparts to learn more about the emerging variant, Fauci said.

"We want to find out scientist to scientist what exactly is going on," Fauci said in an appearance on CNN's "New Day." "You want to find out if in fact it does evade the vaccines that we're doing."

Despite the CDC's announcement that omicron had not been detected in the United States, Fauci didn't rule out the possibility that the variant had already arrived in the nation. "Of course, anything is possible," he said.

Omicron has already been detected in Hong Kong, Belgium, and Israel. Eric Topol, the director of the Scripps Research Translational Institute, told The Washington Post that omicron was the most concerning variant scientists had seen since delta. "It's going to take a really high bar for something to take over for delta, and we don't know whether this is going to do it."

U.S. health officials have already been on alert due to the rising number of infections, hospitalizations, and deaths sweeping through the country in recent weeks, triggered by the arrival of winter - a time when more people gather indoors. They also fear a surge in coronavirus cases during the holiday season as more people travel.