Hong Kong (AFP) - China promised Thursday to take "strong countermeasures" if the US presses ahead with tough new sanctions that target banks over infringements on Hong Kong's autonomy, after Beijing imposed a sweeping security law on the restless financial hub.
Beijing has faced a groundswell of criticism from primarily Western nations over its decision to impose a law outlawing acts of subversion, secession, terrorism and colluding with foreign forces in Hong Kong.
That includes from Britain, which plans to extend citizenship rights to Hong Kongers, and the United States, where Congress on Thursday dialled up the pressure by fast-tracking the new sanctions.
US President Donald Trump still needs to sign off on the Hong Kong Autonomy Act, and has not yet said if he will do so.
It targets Chinese officials and the Hong Kong police, making US sanctions against them mandatory if they are identified in two consecutive government reports as working to impede Hong Kong's freedoms.
Crucially, the act would punish banks -- including blocking loans from US institutions -- if they conduct "significant transactions" with individuals identified as infringing on the city's autonomy.
Earlier Thursday, before the Senate voted on the new measures, Beijing said it "deplores and firmly opposes" the US bill.
"We urge the US to grasp the reality of the situation, stop interfering in Hong Kong affairs and implementing the negative bill, otherwise we will take strong countermeasures," said foreign ministry spokesman Zhao Lijian.
But US Vice President Mike Pence told CNBC Thursday that the security law was a "betrayal" and "unacceptable to freedom-loving people around the world".
Former colonial power Britain has said the law breaches Beijing's "One Country, Two Systems" promise to grant Hong Kongers key liberties -- as well as judicial and legislative autonomy -- until 2047, a promise made as the city was handed back to Beijing in 1997.
As a result, London has announced plans to allow millions of Hong Kongers with British National Overseas status to relocate with their families and eventually apply for citizenship.
"We will live up to our promises to them," Foreign Secretary Dominic Raab told parliament.
That has infuriated Beijing, which says Britain promised not to grant full citizenship rights to Hong Kongers ahead of the handover.
"We firmly oppose this and reserve the right to take corresponding measures," China's embassy in London said Thursday.
But Britain is not alone in its offer.
US lawmakers are also considering a proposed bill offering sanctuary to Hong Kong residents that has received widespread bipartisan support.
Australian leader Scott Morrison said he was "very actively" considering offering Hong Kongers safe haven.
And Taiwan has opened an office to help Hong Kongers wanting to flee.
The security law is controversial because it radically increases China's control over Hong Kong.
Beijing says it is needed to quell seething pro-democracy protests and restore order after a year of political unrest.
But critics fear it will usher in a new era of political repression given similar laws are routinely used to crush dissent on the Chinese mainland.
China says it will have jurisdiction over some cases and has empowered its security agents to operate openly inside Hong Kong for the first time, unconstrained by local laws.
It has also claimed global jurisdiction, saying the law covers national security offences committed overseas -- even by foreigners.
Some trials will be held behind closed doors and without juries, while local police have been granted sweeping surveillance powers that no longer need judicial sign off.
The influential Hong Kong Bar Association said the law dismantles the legal firewall that has existed between Hong Kong's judiciary and China's Communist Party-controlled courts, a key plank of the city's reputation as a business hub.
The new national security offences were "widely drawn", the group said, and "are capable of being applied in a manner that is arbitrary, and that disproportionately interferes with fundamental rights, including the freedom of conscience, expression and assembly".
It also criticised "the total absence of meaningful consultation" with Hong Kongers before the law was passed.
China dismissed the association's concerns, and said their claim the law lacked meaningful consultation was "totally unfounded".
The law -- the wording of which was kept secret until Thursday -- has sent fear coursing through Hong Kong.
One of its most prominent young democracy activists, Nathan Law, announced on Thursday he had fled overseas and will "continue the advocacy work on the international level".
Meanwhile Hong Kong's local government confirmed that a popular protest slogan used over the last year -- "Liberate Hong Kong, Revolution of our Times" -- was now illegal.
It could be heard on the streets as thousands defied a protest ban on Wednesday -- the anniversary of Hong Kong's return to China -- in some of the worst unrest in months.
Police responded with water cannon, pepper spray and tear gas, arresting nearly 400 people -- ten people under the new law.