With an 11 p.m. to 5 a.m. curfew, New York is joining other cities nationwide in imposing restrictions after days of unrest. The limit on the movement of 8.6 million people comes after months of restrictions already imposed because of the coronavirus pandemic.
Cuomo and de Blasio said the outbreaks of violence left them no choice, even as they advocated for peaceful demonstrators who have spoken out against police brutality and racial injustice.
"We can't let violence undermine the message of this moment," de Blasio said. Cuomo blamed "people who are looking to distract and discredit" the protests and said they couldn't be allowed to undermine public safety.
The two leaders, both Democrats, also criticized some police actions as fueling protesters' rage.
Police Commissioner Dermot Shea said earlier Monday on NBC's "Today" that he worried about whether a curfew would be heeded.
"If people think it will, they don't understand what's going on," he said.
The announcement came after rioters overnight had smashed windows and plundered shops in parts of Manhattan, resulting in hundreds of arrests.
A 21-year-old man was shot in the SoHo neighborhood around 12:30 a.m. and was taken to a hospital, police said. They said his injuries were not life-threatening.
Groups of people poured down the sidewalks in Soho and other neighborhoods, including Union Square, breaking into Rolex, Kate Spade and Prada boutiques and electronics stores that have been shuttered for over two months because of the coronavirus.
On Monday morning, police were visible on some of SoHo's hardest-hit streets, and the smell of freshly cut plywood wafted as stores boarded up.
"It's disturbing because I'm 100 percent behind the protesters and against police brutality and bad cops killing people of color whenever they fricking want to, but this is a different story," said Ruby Packard, a teacher and longtime SoHo resident.
Sunday was the third night in a row of mainly peaceful daytime demonstrations, chaotic nights, hot spots of violence and arrests, with the mayor's daughter among those arrested over the weekend.
Thousands of people have taken to the streets across the country to express outrage over Floyd's death and other killings of black people by police and U.S. citizens. Floyd, who was black, died after a white Minneapolis police officer pressed his knee on Floyd's neck for more than eight minutes.
On Sunday, New York City police made some gestures of solidarity with marchers during the day. Some officers knelt with protesters in an intersection as an organizer called out the names of people killed by police. But the police department has also come under criticism for confrontations with demonstrators over the weekend.
Cuomo said some police officers had exacerbated tensions with some "very disturbing" actions.
The head of the city's rank-and-file police union accused the governor of misplacing blame for the chaos.
"We have terrorists burning and looting our city," Police Benevolent Association President Patrick Lynch said.
The Associated Press contributed to this report.