Chicago's mayor has fired the city's police chief, a week after the release of a dash-cam video that showed a white officer fatally shooting a black teenager 16 times.

Mayor Rahm Emanuel called a news conference to announce the dismissal of Superintendent Garry McCarthy.

The mayor praised Mr McCarthy's leadership of the force but called it an "undeniable fact" that the public's trust in the police has eroded.

"Now is the time for fresh eyes and leadership," Mr Emanuel said.

Protesters have been calling for Mr McCarthy's dismissal in response to the handling of the death of Laquan McDonald, a 17-year-old who was killed in October 2014.

The city released police video of the shooting only after a judge ordered it to be made public. The release set off several days of largely peaceful protests. Officer Jason Van Dyke has been charged with first-degree murder.

Mr McCarthy has been chief since May 2011.

The audio-free video shows McDonald walking down the middle of a four-lane street. He appears to veer away from two officers as they emerge from a vehicle, drawing their guns. Van Dyke opens fire from close range and continues firing after McDonald falls to the ground.

Police have said McDonald was carrying a knife, and an autopsy revealed that he had PCP, a hallucinogenic drug, in his system. Cook County State's Attorney Anita Alvarez has said the three-inch blade recovered from the scene had been folded into the handle.

Defence attorney Dan Herbert said his client feared for his life, acted lawfully and that the video does not tell the whole story.

Van Dyke was released from jail on Monday after paying the $150,000 required of his $1.5 million bail.

Prior to his arrival in Chicago, Mr McCarthy was police director in Newark, New Jersey, after rising through the ranks of New York City's police department.