The New York City Police Department's Internal Affairs Division is investigating after a man died Thursday while police were trying to arrest him on Staten Island.

Police say officers approached Eric Garner, 43, after they say they saw him selling untaxed cigarettes on Bay Street in Tompkinsville.

Video published online by the Daily News shows police struggling with Garner. At one point, an officer is seen with his arms around Garner's neck.

He eventually went into cardiac arrest and was pronounced dead at the hospital.

Police say Garner has a long list of prior arrests.

Witnesses tell NY1 officers he was trying to break up a fight right before.

However, police say that is not the case.

In a news briefing Friday, Mayor Bill de Blasio and Police Commissioner William Bratton promised a full investigation into the incident.

"It was very troubling. I watched it the same way a family member would watch it and it was very sad to watch," de Blasio said. "But that being said, we can't pass ultimate judgement based on one video. We need the facts of a full and detailed investigation."

Bratton said that "this would appear to have been a chokehold" but said the investigation will make that final determination.

Bratton said that chokeholds are prohibited by the NYPD.

"The issue of chokeholds has been one that the department began to address as early as the 1980s, and over years, has refined its policies and procedures relative to it, as recently as last year, when another order was issued to the effect that chokeholds are, in fact, prohibited by the New York City Police Department, as they are, in fact, by most police departments in the United States," Bratton said.

According to Bratton, the two officers engaged in the arrest have been assigned to desk duty until the conclusion of the investigation.

The police union is urging that there be no rush to judgment.

In a statement, Patrolmen's Benevolent Association President Patrick J. Lynch said, "Not wanting to be arrested does not grant an individual the right to resist arrest nor does it free the officers of the obligation to make the arrest. In these cases, justice for all involved demands a complete and thorough investigation of all the facts before any conclusions are drawn."

The medical examiner's office says Garner's death is pending further investigation and that no cause has been found yet.

Ramsey Orta, the man who shot the video used by the Daily News, said the police went overboard and falsely accused Garner of selling cigarettes. Sources say Garner did have several illegal packs on him.

"Everybody was telling them, 'He's gone. Like, 'Let him go. He's done,' and cops was like, 'He's alright. He's OK,'" Orta said.

"Big teddy bear," Orta added. "That guy's no harm whatsoever."

Area residents said they also want answers about Eric Garner's death.

Neighbors described him as a gentle, compassionate man and new father.

At a vigil for Garner at the scene Friday, community members said they're outraged.

"I want these officers to get prosecuted also, because that was an act of senseless murder right there," said one person at the vigil.

"It's bad that what happened. It's crazy," said another person at the vigil. "These cops really should be penalized for this."

"So now that we have to worry about police officers as well, it's just like, who do we have to protect us, really? You know what I'm saying?" said a third person at the vigil. "So it's scary. It's really scary."

The Rev. Al Sharpton will lead a march Saturday to call for action in the wake of Garner's death.

NY1 Extra: Mayor, Police Commissioner Address Death of SI Man During Arrest