An estimated 25,000 mourners and police officers from across the country and Canada gathered Saturday morning to pay their final respects to slain NYPD Officer Rafael Ramos.

Officer Ramos and his partner, Officer Wenjian Liu, were fatally shot in an ambush in Brooklyn last Saturday.

The funeral service for Ramos was held at the Christ Tabernacle Church in Glendale, Queens, where Ramos served as a parishioner. About 800 people were packed inside.

The 40-year-old father of two was set to graduate as a chaplain the day he died. NYPD Commissioner Bill Bratton posthumously promoted Ramos as honorary chaplain of the 84th Precinct during the funeral service.

Outside the church on Myrtle Avenue, a sea of police officers in blue flooded the surrounding area starting early Saturday morning.

Vice President Joe Biden was in attendance, and delivered an impassioned speech to the crowd. New York City Mayor Bill de Blasio also spoke at the service, as did Bratton and New York Gov. Andrew Cuomo.

Hundreds of officers who were positioned outside the church watching the ceremony on giant TV screens turned their backs on the mayor as he spoke during the service. The reaction followed comments from police union officials who said that de Blasio fostered mistrust toward police amid widespread anti-police protests.

JetBlue flew in more than 730 officers from departments that include Chicago, Boston, Los Angeles and several Florida cities for free to attend the wake and funeral. They all stood at attention as 12 helicopters did a fly-over.

Security was extremely high, with officers stationed on rooftops, K-9 units on the ground and helicopters in the air.

Close to 1,000 police officers from Long Island were in attendance. They told News 12 that it was important for them to make the trip so that they could pay their respects to one of their own.

Ramos was to be buried in Cypress Hills Cemetery in Brooklyn.

Funeral arrangements for Officer Liu have not yet been finalized.