The city's Department of Education is setting up a hotline for principals to call when they need cleaning supplies or personal protective equipment for "rapid resupply" COVID-19 protections once the city's schools reopen in September, Mayor Bill de Blasio announced on Monday morning.

"We need our educators and our staff to know that all of this support will be in place for them ahead of school opening, and then if anything comes up where there needs to be rapid response, we can do rapid resupply to schools just a phone call away," de Blasio said during a virtual news conference.

In a video intended to reassure students, teachers, and parents that schools are ready to safely reopen, the city announced myriad cleaning supplies expected to be deployed to prevent the spread of coronavirus: 4 million face masks, 3.5 million bottles of hand sanitizer, and 80,000 containers of disinfectant wipes.

About 7,350 staffers will disinfect buildings after school and throughout the day using 3,750 electrostatic sprayers for touch-free disinfecting. Some 210,000 signs about COVID-19 safety measures will be placed throughout schools. Rooms without ventilation won't be used by students or staff.

"We're going to send them the supplies in great bulk before school begins and constantly resupply as needed," de Blasio said. "The point that we keep making, whatever the school needs, it will get."

The principals' hotline will be up and running this week, the mayor said.

Chancellor Richard Carranza will be doing spot checks at schools to ensure safety protocols are being followed as well, the mayor said.

But many details are still being worked out for a number of protocols just weeks away from the tentative start date of September 10th.

For instance, during remote learning, students may not have a teacher from their school during instruction, Carranza said. The goal is that teachers from students' specific school would instruct them, but it's not a guarantee.

"Our goal has always been that students who are remote learning will have teachers from their school or a teacher from their school, there will be some continuity," Carranza said. "Obviously, that is our goal, but that's not a guarantee because it's going to depend on how many teachers from that school are in remote-mode, how many are in in-person learning."

"We are in the throes of all of those detailed planning processes right now. We're working very closely with our unions," Carranza said.

The announcements build on NYC's plans to keep school buildings properly sanitized and socially distanced for 1.1 million public school students and the teachers, principals, custodians, and lunch workers that keep schools functioning. Last week, the principals' and teachers' union as well as the unions for lunch workers and school aides called on the mayor to postpone reopening schools.

"The slow rollout of guidance has forced us to once again address an unfortunate truth: schools will not be ready to open for in-person instruction on September 10th," the Council of School Supervisors and Administrators' president Mark F. Cannizzaro wrote to de Blasio last week. "When will schools receive PPE, thermometers, signage, hand sanitizers and cleaning materials to supply with the safety protocols?" Cannizzaro asked, among other questions on staffing, ventilation system repairs, and other guidance. At the time, a Department of Education spokesperson said "dedicated school leaders and educators will show up" for students like they have every year.

On Monday, when asked when the department would be distributing the cleaning supplies and PPE, DOE spokesperson Nathaniel Styer said the distribution has begun and will continue. Additionally, staffing concerns are being addressed through reassignments and the Absent Teacher Reserve, Styer said.

This article has been updated with additional information from the Department of Education.