WASHINGTON (NewsNation Now) — On the heels of President Joe Biden announcing a new plan to tackle COVID-19 in schools, he and first lady Jill Biden are stopping at a local elementary school to encourage safety in classrooms.

Biden called some Republican governors “cavalier” on Friday for resisting his call for far-reaching new federal coronavirus vaccine requirements he hopes will curb the surging delta variant.

Biden visited a public school just a short drive from the White House to make the case for new rules he set out a day earlier that could impact 100 million Americans.

He also pushed back against Republicans, and some union officials, who say he is overreaching his authority. Biden said they were shirking their responsibility to young Americans.

“I am so disappointed that particularly some Republican governors have been so cavalier with the health of these kids, so cavalier with the health of their communities,” Biden said during a visit to Brookland Middle School in northeast D.C. “This isn’t a game”

The visit comes after Biden announced Thursday night several measures he planned to take that would make back to school safer with the delta variant causing a rise in COVID-19 cases among children.

“We know that if schools follow the science, and implement the safety measures like testing, masking, adequate ventilation systems, social distancing, and vaccinations, then children can be safe from COVID-19 in schools,” Biden stated in his speech to the nation.

Additional federal financial support will be sent by the Department of Education to assist schools in safely operating, including additional funding for testing.

Separately, the Department of Health and Human Services will require vaccinations in Head Start Programs, as well as schools run by the Department of Defense and Bureau of Indian Education, affecting about 300,000 employees.

Biden has encouraged COVID-19 vaccine requirements in settings like schools, workplaces and university campuses.

While multiple cities have voted to make vaccines mandatory for staff members, students have mostly been encouraged but not required to get a COVID-19 shot. On Thursday, the Los Angeles Board of Education became among the first to require all students 12 and older to be fully vaccinated in the the nation’s second-largest school district.

Biden has stressed the need for mask mandates in schools to protect children who are unvaccinated against COVID-19. Mask mandates in classrooms has remained a polarizing issue, with some states outright banning any school district from imposing a mask requirement.

The Department of Education has announced a grant program to finance the budgets for school districts that lose money by going against state law and imposing mask requirements in the classroom.

First lady Jill Biden, who joined the president for the school visit, echoed Biden’s message that getting more Americans vaccinated was essential to keep schools open and helping working parents.

“We owe them a promise to keep their schools open as safe as possible,” the first lady said. “We owe them a commitment to follow the science. We owe them unity, so that we can fight the virus, not each other.”

More than 177 million Americans are fully vaccinated against the coronavirus, but confirmed cases have shot up in recent weeks to an average of about 140,000 per day with on average about 1,000 deaths, according to data from the Centers for Disease Control and Prevention.

Most of the spread — and the vast majority of severe illness and death — is occurring among those not yet fully vaccinated. So-called breakthrough infections in vaccinated people occur, but tend to be far less dangerous.