Hong Kong's leader has said he is ready to start talks with protest leaders as soon as next week, suggesting a breakthrough in a political crisis that has seen activists occupy the city's key business districts for almost three weeks.

Speaking on Thursday, Chief Executive Leung Chun-ying said: "As long as students or other sectors in Hong Kong are prepared to focus on this issue, yes we are ready, we are prepared to start the dialogue.

"This is why over the past few days ... we expressed the wish to students that we'd like to start the dialogue, to discuss universal suffrage, as soon as we can, and hopefully within the following week."

Leung did not directly respond to questions about when police would move in to clear out protesters.

Demonstrators took over major roads and streets in the city's business districts on September 28 to press for a greater say in choosing the city's leader in the territory's first direct elections.

Leung said authorities had tolerated the civil disobedience movement to date, but it "cannot go on indefinitely".

"Going forward, we cannot allow the occupying of streets to have a negative impact on Hong Kong society. Police will use appropriate methods to deal with this problem," he said.

Authorities angered protesters when they called off a scheduled meeting with student leaders last week, saying talks were unlikely to produce constructive results.

Protesters oppose the Chinese central government's ruling that a committee stacked with pro-Beijing elites should screen candidates in the territory's first direct elections, promised in 2017.

That effectively means that the government can vet the nominees before they go to a public vote.

Leung said there was scope for negotiations in how the committee that nominates candidates was formed.

"In the second round of consultation, we can still listen to everyone's views. There is still room to discuss issues including the exact formation of the nomination committee," he said.

Meanwhile, six police officers were removed from their posts and reassigned after footage of the officers in plain clothes beating up a protester, were shown on local television channels on Wednesday.

The Police have promised an impartial investigation into the incident.

Source: Al Jazeera and agencies