New York City Mayor Bill de Blasio received an icy reception at an NYPD graduation ceremony Monday morning.

Those in attendance at the Madison Square Garden ceremony heckled the mayor while he addressed the city's newest officers.

"All of us here on this stage, we have a responsibility to keep you safe," said de Blasio. "We ask you to selflessly protect others, but it's our job to protect you."

The relationship between the NYPD and City Hall has been rocky over the past several weeks. PBA President Patrick Lynch accused the mayor of throwing city officers "under the bus" after a grand jury decided not to indict an officer in the death of Eric Garner in Staten Island.

Officers turned their backs on the mayor during the funeral for slain NYPD Officer Rafael Ramos over the weekend. Ramos has since been posthumously promoted to detective.