Hong Kong's embattled leader abandoned a State of the Union-style speech on Wednesday after she was heckled by opposition lawmakers during chaotic scenes inside the city's legislature.

The speech by chief executive Carrie Lam was billed as an attempt to win hearts and minds after four months of seething pro-democracy protests.

But it instead laid bare the intense polarisation coursing through the semi-autonomous financial hub after weeks of huge and increasingly violent protests.

Lam tried twice to begin her policy address inside the Legislative Council which had opened for a new session some three months after it was trashed by masked protesters.

But pro-democracy lawmakers, who form a minority of the pro-Beijing legislature, shouted her down.

One even used a pocket projector to broadcast protest slogans behind Lam as she stood on the podium, and later donned a face mask of Chinese President Xi Jinping.

After failing to deliver the address for a second time, Lam left the building and her office announced that she would release a pre-recorded video of the speech instead.

It is the first time in Hong Kong's history that a chief executive or governor has been unable to deliver the annual address in person since the tradition began in 1948.

The chaos inside the Hong Kong legislature comes after a summer of huge and increasingly violent democracy protests as popular anger explodes over sliding freedoms and living standards following two decades of Chinese rule.

There is huge pressure on Lam — who currently boasts historically low approval ratings — to unveil flagship measures that might lower some of the anger on the streets.

An advance copy of the speech seen by AFP shows Lam will focus on housing and land shortages in a city that has one of the least affordable property markets in the world and notoriously high rents.

But there are no major concessions to protesters.

Congress mulls rights bill

At a briefing on Tuesday, Lam stuck to her oft-repeated stance that bending to violent demonstrations would be unacceptable.

“For concessions to be made simply because of escalating violence will only make the situation worse. On the other hand, we should consider every means to end the violence,” she said.

The core demands of protesters include an independent inquiry into the police, an amnesty for the more than 2,500 people arrested and the right for Hong Kongers to freely elect their leaders.

Both Lam and Beijing have repeatedly dismissed those demands.

Millions have taken to the streets of Hong Kong, initially against a now-dropped bid by its leaders to allow extraditions to the authoritarian Chinese mainland.

The months-long movement has expanded into a broader pro-democracy push in the territory where activists say freedoms are being eroded by Beijing, contrary to a deal that outlined Hong Kong's 1997 return to China from British colonial rule.

Lam's speech comes after the United States House of Representatives passed a bill late on Tuesday that aims to defend civil rights in Hong Kong and has drawn rare bipartisan support in a polarised Congress.

China, which has accused “external forces” of fuelling weeks of unrest in the city, expressed its “strong indignation” over the bill and told Washington to “stop meddling”.

The Hong Kong Rights and Democracy Act would link the city's special trading status with the US to an annual State Department certification that authorities are respecting human rights and the rule of law.

It would also require the US president to identify and sanction the people responsible for the erosion of autonomy and serious abuses of human rights in Hong Kong.

The House also approved a related bill to prohibit the export of certain non-lethal crowd control items such as tear gas to Hong Kong.