The city's teachers union hosts its annual spring conference.
Mayor Bill de Blasio joined hundreds of members of the United Federation of Teachers at the Hilton Hotel in Midtown Saturday.
De Blasio vowed to always support public schools, and warned of funding cuts from Washington.
The Mayor says teachers across the country are facing an uphill battle against Education Secretary Betsy deVos
"People like her are actually having the reverse impact they were intended to have," de Blasio said. "Public school parents all over the country are waking up saying 'wait a minute, I didn't vote for that.' Even the ones who voted differently than I believe are saying 'wait a minute, you didn't tell me you were going to take money away from public schools. You didn't tell me you were going to hurt my children's education."
DeVos supports school vouchers and charter schools.
She has said federal funding cannot help solve issues in public schools.