Wilson, who said he was acting in self-defense and that his conscience is clear, had been on administrative leave and in seclusion since the incident.

Ferguson's mayor said he had not asked for Wilson's resignation but Knowles wanted the city to turn a page, even though the officer had expressed an interest "in a future here."

Knowles said his focus was on how to rebuild trust in the city, where the shooting exposed long-standing grievances about race relations both in Ferguson and across the country.

Veteran civil rights activist Rev. Al Sharpton preached on Sunday to a congregation of some 2,500 worshippers at the St. Louis church where Michael Brown's funeral was held in August. The dead teen's parents were among the congregation.

Wilson's departure was long anticipated because of the potential risks to his own safety and the deep rifts that have emerged in Ferguson between the mostly white police force and the majority black population.

Some critics want the police chief to resign as well. During the news conference on Sunday, the chief, Tom Jackson, said he had no plans to resign. The mayor said no changes in the department's leadership were in the works.

President Barack Obama will meet on Monday with civil rights leaders, elected officials and law enforcement officials from around the country to discuss how communities and police can work together to build trust to strengthen neighborhoods across the country, the White House said in a statement on Sunday.

He will also meet with cabinet members to discuss a review Obama ordered in August of federal programs that provide equipment to local law enforcement agencies, the White House said.