Mayor Eric Adams introduced on Friday that New York Metropolis would search to maintain its faculty masks mandate in place for kids below 5 and that town would attraction an order by a decide on Staten Island that moved earlier within the day to strike it down.

Mr. Adams additionally mentioned town would ask for a keep in order that the masks mandate might stay in impact. The mayor had earlier mentioned that the mandate can be lifted beginning on Monday if coronavirus instances didn’t rise.

Mr. Adams mentioned that preschoolers ought to proceed to put on masks as a result of they’re too younger to be vaccinated and instances are rising once more within the metropolis, an increase fueled by an Omicron subvariant, BA.2, that’s now dominant in the US.

“New Yorkers, we wish you to be ready, not panicked,” Mr. Adams mentioned at a information convention at Metropolis Corridor.

Town’s well being commissioner, Dr. Ashwin Vasan, requested mother and father for “persistence and beauty” as town tried to maintain New Yorkers protected.

“We’re recommending to attend somewhat bit longer earlier than making masks elective for this age group,” Dr. Vasan mentioned on the information convention.

Mr. Adams had introduced final week that he deliberate to cease requiring masks for kids below 5 at baby care facilities and preschools beginning this Monday. However instances have began to rise during the last month, from about 500 every day instances in early March to about 1,250 every day instances now. Town might quickly transfer from a low danger stage to a medium danger stage, in response to a brand new color-coded alert system primarily based on pointers from the Facilities for Illness Management and Prevention; Manhattan particularly is on the cusp.

“We count on to maneuver to a better danger class in a matter of weeks,” Dr. Vasan mentioned.

Mr. Adams, a Democrat who took workplace in January, has targeted on town’s restoration from the pandemic and has rolled again some restrictions, together with ending a proof-of-vaccination mandate for eating places, gyms and leisure venues, referred to as the Key to N.Y.C. program, and eradicating a masks mandate for college students in kindergarten by way of twelfth grade. He had confronted strain from some mother and father to finish the masks mandate for preschool-aged kids.

He launched the alert system final month, and town issued “beneficial actions” for every danger stage. In response to the system, town ought to think about reinstating the Key to N.Y.C. program, on the medium danger stage. If the danger stage turns into excessive or extraordinarily excessive, town might as soon as once more require masks indoors or urge residents to shelter in place.

Well being specialists fear that BA.2, which has fueled case surges in Europe and Asia, might result in one other wave of the pandemic within the metropolis, and presumably the nation. They imagine that the true variety of instances in New York is likely to be larger than the information suggests, as a result of many individuals are testing at house, with no official reporting of outcomes.

Hospitalizations have remained low in New York Metropolis during the last month and are presently at about 13 per day, though hospitalizations are sometimes a lagging indicator. There have been about 1,000 hospitalizations a day in January, when instances final soared.

Mr. Adams additionally mentioned Friday that town deliberate to distribute about six million house exams this month. Requested if he would think about reinstating a masks mandate for older college students, Mr. Adams mentioned he would “pivot and shift” relying on the information and recommendation from his well being group.

Dr. Vasan inspired New Yorkers to get booster pictures and to put on masks in public indoor settings, stating that he was carrying a masks on the information convention. He mentioned that he wished to make use of an “abundance of warning” for younger kids, who had larger hospitalization charges through the Omicron surge.

BA.2 — essentially the most transmissible model of the coronavirus but recognized — accounts for greater than half of latest virus instances in the US, the C.D.C. mentioned this week. It accounts for about 70 % of instances within the area that features New York, New Jersey and Puerto Rico.

The masks mandate for kids below 5 applies to town’s 4-Ok and 3-Ok preschool lecture rooms, which serve about 95,000 college students, and to all different preschool and baby care facilities. New York by no means required kids below 2 to put on masks in day care facilities.

No matter what occurs in courtroom, Mr. Adams inspired mother and father to proceed to have their kids below 5 put on masks.

“You must hold your masks in your kids,” he mentioned.

The decide who dominated on the preschool masks mandate on Friday, Ralph Porzio of the State Supreme Court docket on Staten Island, wrote in his order that the mandate was “arbitrary, capricious, and unreasonable.” Mr. Adams mentioned he was assured that town would prevail in its attraction and that he would let mother and father know what to anticipate on Monday.

“We actually imagine that is inside our powers to execute what’s finest for New York,” he mentioned.

Michael Chessa, a lawyer for the mother and father who challenged the mandate, mentioned they wished mother and father to have a alternative and didn’t imagine town had offered clear benchmarks for eradicating the requirement.

“Merely saying that instances are on the rise and 2- to 4-year-olds can’t be vaccinated, that’s simply unacceptable,” he mentioned. “It was fantastic within the spring of 2020, however we’re effectively past that now.”