WATCH: Biden's plan to open schools in first 100 days to cost 'tens of billions of dollars'

In a briefing on Tuesday, President-elect Joe Biden said that his plan for his first 100 days in office is to open schools for grades K-8. He made no such provision for high school students.

"Another 100 day challenge is opening most of our K-8 schools by the end of the first 100 days in the spring.

"Look, we can only do that if Congress provides the necessary funding so we get schools, districts, communities, states, the resources they need for so many things that aren't there already in a tight budget."

Biden said that "They need funding for testing to help reopen schools. More funding for transportation so students can maintain social distances on buses. They need it for school buildings, for additional cleaning service, for protective equipment.

"Ventilation systems. This is going to require an additional tens of billions of dollars to get this done."

Biden had previously promised that getting schools open would be a top priority, and in fact, the CDC and many pediatricians have already said that children are not vectors of COVID.

Teachers unions across the country have said that they will not return to schools over fears for their own safety, yet there has not been evidence to suggest that school children pose a grave risk to each other or to educators.

While Biden is making extremely expensive provisions to open schools for those in elementary and middle schools, high schoolers, who have already missed nearly a year of school, will miss another half year.

School closures have had an astoundingly detrimental affect on students' performance, mental health, and academic readiness.

Biden was endorsed by the National Education Association, the largest union in the nation, that represents nearly 3 million educators and administrators across the country. The NEA presented their plan for school reopening to the Biden team, which included vast overhauls of school buildings, funding critical race and gender theory, and many other pet, progressive projects.

During his last days in office, President Trump signed an executive order to allow states to distribute COVID relief to parents who would send their kids to open schools, instead of waiting for unions and elected leaders to get their acts together and allow children back into the classroom.