HONG KONG • China accused the United States yesterday of seeking to "destroy" Hong Kong and threatened retaliation after Congress passed new legislation supporting the pro-democracy movement that has thrown the city into nearly six months of turmoil.

Foreign Minister Wang Yi said the passage of the Hong Kong Human Rights and Democracy Act "indulges violent criminals" whom China blames for the worsening unrest, and aims to "muddle or even destroy Hong Kong".

The legislation - which now awaits United States President Donald Trump's signature into law - backs universal suffrage, freedom from arbitrary arrest, and sanctions against those who contravene such principles.

It was passed by the House of Representatives on Wednesday despite warnings from China, which angrily rejects criticism of its handling of Hong Kong.

Hong Kong's months of protests began with a now-shelved Bill to allow extraditions to mainland China, which revived fears that Beijing was slicing into the city's freedoms.

Millions of angry citizens have taken to the streets in giant marches, and protesters have repeatedly clashed with police in a movement that has widened to include calls for democracy and an inquiry into alleged police brutality.

The turmoil has already tipped Hong Kong's economy into recession, and the threat of a change in trade status brought fresh gloom.

Mr Wang, Beijing's top diplomat, condemned the Bill as "naked interference in China's internal affairs", according to the Foreign Ministry, which said the comments were made during a meeting in Beijing with former US defence secretary William Cohen.

A Foreign Ministry spokesman also vowed that China would "take effective measures to resolutely fight back", giving no details.

Separately, in a statement, the Hong Kong government said the two Acts would interfere in the internal affairs of Hong Kong and would not be conducive to de-escalating the situation in the city.

Hong Kong is a semi-autonomous Chinese region, and US policy treats its economy as separate from the rest of China. That has been a key factor in the city's rise as a global financial hub, and left it exempt from the crippling tariffs imposed by Mr Trump's administration.

The new US Bill would require an annual review of that status, which could be revoked if the city's unique freedoms are quashed.

Beijing has repeatedly said it may act if Hong Kong spirals out of control, and China's state media said the US legislation would not change that calculus. "Some may expect this to deter Beijing," the government mouthpiece Global Times said. "Such thinking is naive."

But President Xi Jinping's government has a problem: Any strong measure against the US also risks backfiring on China. China's retaliation since Mr Trump kicked off a trade war last year has mostly been tit-for-tat tariffs, and always with the caveat that it was left with no other choice.

In other areas where it has been hit by the US - Taiwan arms sales, sanctions over human rights abuses in the far west region of Xinjiang and putting Huawei Technologies on a blacklist - China has held fire despite threats to hit back.

"It's worth noting that the US can do more damage to China than China can do to the US," said Dr Shi Yinhong, an adviser to China's Cabinet who is a professor of international relations at Renmin University in Beijing.

"The imminent retaliation from China would be on the ongoing trade talks," said Dr Huiyao Wang, another adviser to China's Cabinet and founder of the Centre for China and Globalisation in Beijing.

"The Hong Kong Bill will do tremendous damage to the prospect of a trade deal and stall the negotiation process as China's side won't engage positively with US counterparts."

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