The mayor’s daughter was one of 345 people arrested at protests in New York City on Saturday, and was briefly detained, then released from custody.
During a press conference about the protests on Monday, Mr de Blasio told reporters, that he is proud of his daughter for fighting for change she believes in.
“I love my daughter deeply, I honour her. She is such a good human being, she only wants to do good in the world, she wants to see a better and a more peaceful world. She believes a lot of change is needed,” the mayor said.
“I’m proud of her that she cares so much and she was willing to go out there and do something about it,” Mr de Blasio added.
Protests began last week, when Mr Floyd died after former Minneapolis police officer, Derek Chauvin, knelt on his neck while detaining him.
Mr Chauvin was arrested and charged with third-degree murder and manslaughter on Friday and may face further charges in the future, according to county attorney Mike Freeman.
Protests, that are being held in opposition to police brutality against Black Americans, initially started in Minneapolis last week, but spread to Los Angeles and New York City, among other cities in the US over the weekend.
Mr de Blasio said that he and his wife, Chirlane McCray, did not know that their 25-year-old daughter was protesting, but confirmed that she believed she was demonstrating peacefully.
“She recounted the story in detail to me. She was acting peacefully. She believes that everything she did was in the spirit of peaceful respectful protest,” he said.
“And the bottom line is, I will let her speak for herself in any way she wants to, but I admire that she was out there trying to change something that she thought was unjust and doing it in a peaceful manner.”
Some of the protests across the US have turned violent at night, and police have clashed with protesters in various cities.
Footage has shown police in different cities in the US using excessive force, including an incident in New York City, where a police car drove into a group of protesters.
During the press conference on Monday, Mr de Blasio confirmed that he has met with community leaders, and reiterated that his stance is that the protests should be peaceful.
The mayor said: “What I heard overwhelmingly was a desire to keep things peaceful for people to work on change in a positive, constructive way.”
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