Mayor Bill de Blasio dismissed warnings from an NYPD labor union that a cop’s conviction Thursday for shooting an unarmed man in a darkened housing-project stairwell, would have a chilling effect on patrols.

Speaking at an unrelated news conference, the mayor said that the NYPD would continue vertical patrols in the housing projects, in which police officers climb and descend building staircases to search for wrongdoing.

“Vertical patrols are necessary as part of keeping our public housing residents safe,” de Blasio told reporters.

Officer Peter Liang was found guilty Thursday of manslaughter and other crimes in the 2014 death of Akai Gurley. Liang, who has since been fired, shot Gurley at the Pink Houses while doing a vertical patrol. He and his partner argued over who would need to call in the shooting, and the two did not help resuscitate the man.

The head of the rank-and-file officers’ union, Patrick Lynch of the Patrolmen’s Benevolent Association, said that Liang’s conviction “absolutely will have a chilling effect on every New York City police officer wondering how is it we are supposed to do our job in this anti-police atmosphere.”

De Blasio declined to say whether he thinks that Liang should serve prison time.

“The most important thing I want to say isto the family of Akai Gurley,” de Blasio said. “I hope this brings them a sense of closure.”