NEW YORK — After five years of investigations and protests, the New York City Police Department on Monday fired an officer involved in the 2014 chokehold death of the black man whose dying cries of “I can’t breathe” fueled a national debate over race and police use of force.

Police Commissioner James O'Neill said he fired Daniel Pantaleo, who is white, based on a recent recommendation of a department disciplinary judge. He said it was clear Pantaleo "can no longer effectively serve as a New York City police officer."

"None of us can take back our decisions," O'Neill said, "especially when they lead to the death of another human being."

Asked whether Mayor Bill de Blasio forced his hand, O'Neill said the dismissal was his choice. "This is the decision that the police commissioner makes," he said, calling Eric Garner's death an "irreversible tragedy" that "must have a consequence."

The president of the police union, Patrick Lynch, accused O'Neill of choosing "politics and his own self-interest over the police officers he claims to lead."

Lynch urged police officers to "proceed with the utmost caution in this new reality, in which they may be deemed 'reckless' just for doing their job."

"Now it is time for every police officer in this city to make their own choice," he said in a statement. "We will uphold our oath, but we cannot and will not do so by needlessly jeopardizing our careers or personal safety."

Video of the confrontation led to years of protests and calls by black activists and liberal politicians for Pantaleo to lose his job. City officials had long insisted that they could not take action until criminal investigations were complete.

A state grand jury declined to indict Pantaleo in 2014. Federal authorities, however, kept a civil rights investigation open for five years before announcing last month they would not bring charges.

Pantaleo's lawyer has insisted the officer used a reasonable amount of force and did not mean to hurt Garner.

O'Neill said Pantaleo initially placed Garner in a chokehold as the two men stumbled backward into a glass window. That, he said, was understandable, given the struggle.

But after the officers got Garner on the ground, Pantaleo did not relax his grip but "kept his hands clasped and maintained the chokehold." That, he said, was the mistake that cost him his job.

"That exigent circumstance no longer existed when they moved to the ground," O'Neill said.

Garner's death came at a time of a growing public outcry over police killings of unarmed black men that sparked the national Black Lives Matter movement.

Just weeks later, protests erupted in Ferguson, Missouri, over the fatal shooting of 18-year-old Michael Brown. And later in 2014, a man angry about the Garner and Brown cases shot two New York City police officers to death in their cruiser in retribution.

The Rev. Al Sharpton said Garner's family was "relieved but not celebratory."

"Pantaleo will go home a terminated man, but this family had to go to a funeral," Sharpton said at a news conference.

Garner's daughter, Emerald Snipes Garner, thanked O'Neill "for doing the right thing." She said she is urging lawmakers to make it a state and federal crime— not just an administrative violation— for any police officer to use a chokehold.

"I should not be here standing with my brother, fatherless," she said. "He's fired, but the fight is not over."

De Blasio never said whether he believed Pantaleo should lose his job but promised "justice" to the slain man's family.

At a recent administrative trial at police headquarters, Pantaleo's lawyers argued he used an approved "seat belt" technique to subdue Garner, who refused to be handcuffed after officers accused him of selling untaxed cigarettes.

In a bystander's video, it appeared that Pantaleo initially tried to use two approved restraint tactics on Garner, who was much larger at 6-foot-2 (188 centimeters) and about 400 pounds (180 kilograms), but ended up wrapping his arm around Garner's neck for about seven seconds as they struggled against a glass storefront window and fell to the sidewalk.

The footage showed Garner, who was 43 at the time, crying out, "I can't breathe," at least 11 times before he fell unconscious. The medical examiner's office said a chokehold contributed to Garner's death.

Questions about the handling of the case have dogged de Blasio during his longshot run for president, with some protesters at the recent debate in Detroit chanting, “Fire Pantaleo.”