The Black Lives Matter movement “has changed the national discussion for the better,” Mayor Bill de Blasio said Monday morning in an interview with CNN’s “New Day.”

The Democratic mayor, who appeared alongside first lady Chirlane McCray, commended the demonstrations that began in response to a spate of police-involved shooting deaths of black men as a “force for good” and for “shining a light on the problems we have in race relations across this country.”

His words appeared to run counter to those of his police commissioner, William Bratton, a day earlier in an interview with NBC’s “Meet the Press.”

Bratton said the movement, which ramped up after last week’s deaths of two black men in Louisiana and Minnesota and five police officers in Dallas, is an effort “to portray police and the police profession in a very negative way.”

The top cop acknowledged that there are bad players — “we have racists, we have brutal people, we have criminals” — within the ranks of police nationally, but they do not represent the majority of law enforcement officials.

De Blasio and Bratton were to appear together later Monday for a news conference at NYPD headquarters in lower Manhattan on citywide crime.

Former Mayor Rudy Giuliani had much stronger criticism of Black Lives Matter and told CBS’ “Face the Nation” on Sunday that the slogan is “inherently racist.”

The Republican also added that he believes the parents of black children should teach them to respect police and stay away from negative neighborhood influences, saying, “There’s a 99 percent chance they’re going to kill you, not the police.”