Facing heat from the police union, New York City Mayor Bill de Blasio stood by his comments from earlier this week that his biracial son needs to take special precautions around cops.

De Blasio explained after the non-indictment of Eric Garner that he and his wife "had to literally train" their son Dante how to handle encounters with police -- an experience shared by the parents of other African-American children around the country. The head of the city's police union said de Blasio's statement "threw cops under the bus."

Speaking on ABC's "This Week" with George Stephanopoulos on Sunday, de Blasio said there was "so much misunderstanding" about what he meant.

"What parents have done for decades who have children of color, especially young men of color, is train them to be very careful when they have a connection with a police officer," de Blasio said.

"It's different for a white child. That's just the reality in this country," de Blasio went on. "And with Dante, very early on with my son, we said, look, if a police officer stops you, do everything he tells you to do, don't move suddenly, don't reach for your cell phone, because we knew, sadly, there's a greater chance it might be misinterpreted if it was a young man of color."

The lack of indictments in the deaths of Michael Brown and Eric Garner has led to widespread protests and sparked a national conversation on police use of force, particularly when it comes to African-American men.