Hong Kong's government has called off talks with pro-democracy students aimed at ending nearly two weeks of protests and mass sit-ins that have paralysed parts of the city.

Chief Secretary Carrie Lam, seen as the government's second highest official, said that talks scheduled for Friday would not go ahead because they were "seriously undermined" by remarks from the student leaders.

"It's impossible to have a constructive meeting tomorrow," Lam told reporters. "The dialogue cannot be deployed as an excuse to incite more people to join the protest.”

Inside Story - Beijing's options in Hong Kong

Her comments came just hours after protest leaders vowed to ratchet up their occupation of key parts of the city if they failed to win concessions from the government.

Parts of the vital financial hub have been paralysed for more than a week by demonstrations calling for Beijing to grant the former British colony full democracy and for the city's Chief Executive Leung Chun-ying to resign.

Pro-democracy lawmakers also threw their weight behind the protesters on Thursday saying they would use their powers to disrupt the workings of the Hong Kong government inside the city's parliament by gridlocking the committees they currently control.

"Hong Kong has entered an era of disobedience and non-cooperation," said pro-democracy leader Alan Leong.

The protesters are demanding free and open elections to select the former British colony's next leader in 2017. China's Communist authorities insist only pre-approved candidates will be able to run, a system critics dismiss as "fake democracy".

Handed back to Chinese rule in 1997, Hong Kong is governed under a "one country, two systems" deal that guarantees civil liberties not seen on the mainland, including freedom of speech and the right to protest.

Source: Agencies