NEW YORK — As coronavirus cases increase among school-aged children, the city will ramp up its surveillance testing in schools with a new push officials are calling "Stay Safe and Stay Open."

The number of students being randomly tested for coronavirus will double from 40,000 to 80,000, Mayor Bill de Blasio announced on Tuesday, and will now include both vaccinated and unvaccinated students.

Staff will also be able to be tested if there are enough PCR tests at the school. If there aren't, the staffers will be given rapid test kits, the city said.

When there's a positive case in a classroom, every person in the classroom will also be given a rapid test kit, in an effort to stop the virus from spreading but to also reduce unnecessary absences among students without symptoms who test negative, the city said. Those students who test negative will be able to return to their classrooms.

The new testing regime extends to pre-K and 3-K classrooms as well. 

De Blasio said that the new rules were based on data about how COVID-19 spreads, such as that 98% of close contacts of COVID-19 cases do not test positive for the virus. 

"The jury has come back," de Blasio said at a news conference. "We have a lot of evidence now that's told us this is the approach that's going to work for the future."

The city will also ask parents to have children tested before returning to school on January 3 — though they won't require it. De Blasio said that the city will add 40 more testing sites around the boroughs ahead of the return to school. 

Mayor-elect Eric Adams and Gov. Kathy Hochul joined de Blasio at the news conference. Hochul said she was directing state agencies to provide 2 million tests to the city for use in public schools. 

De Blasio said that the testing approach in schools was developed together with the incoming administration, which will be in place by the time schools open.

"Your children are safer in school," Adams said. "The numbers speak for themselves."

So far, 330,000 students who are not vaccinated have consented to testing in schools for this school year, de Blasio said. He added that he expects the number to rise when the testing regimen starts including vaccinated children. 

Students will be expected to bring their test kits home with them, but parents will also be able to pick up the kits at school as well, de Blasio said.

In a statement, Michael Mulgrew, president of the United Federation of Teachers, said the union hoped that the city could get its school COVID-19 monitoring situation room "rebuilt, after basically coming apart in the last several weeks" in time for classes resuming. 

"We are moving closer to a safe re-opening of school next week," Mulgrew said. "But we are not there yet."

De Blasio denied in the news conference that the situation room was struggling to adequately respond to cases in schools. 

"The situation room will continue to play a number of important functions beyond that role of monitoring for widespread transmission," said Dr. Dave Chokshi, the city's health commissioner.