With New York City's public schools already facing massive disruptions because coronavirus crisis, another blow: more than half a billion dollars in budget cuts, including to some of Mayor Bill de Blasio's signature programs.

"Things that might have been a priority you know two months ago, three months ago, can't be a priority right now," de Blasio said.

Among the proposed reductions for the next budget year — a $100 million hit to Fair Student Funding, money provided directly to schools. Earlier this week, the mayor said better-funded schools would be the focus of the cuts.

"For schools that have had more than a 100 percent in a time of sacrifice, we're going to ask them to help and sacrifice and cut back some so that we can, you know, get this together," he said.

The leader of the union representing principals and administrators says the cuts will only make it harder to gain academic ground lost during months of students being out of classrooms.

"It's simply that the cuts are going to make it more challenging. And no one's saying that there doesn't have to be cuts -- we understand -- it's just that going after the Fair Student Funding right now, there need to be other areas that need to be looked at," said Mark Cannizzaro, president of the Council of School Supervisors and Administrators.

The mayor also wants to slash $67 million in professional development programs and save $49 million by pausing programs under his Equity and Excellence agenda — including one that provides extra guidance counseling and another that works to steer more students toward college.

The mayor also proposes to delay expansion of pre-kindergarten for three-year-olds, saving $43 million.

The plan also includes a $40 million hiring freeze on teachers -- other than those in the city's absent teacher reserve. It saves another $10 million by delaying plans to air condition every city classroom.

"Things like that just inherently have to wait compared to food shelter safety health. There are things that have to wait," the mayor said.