China's office in Hong Kong on Saturday denounced Washington's decision to sanction key officials over sliding freedoms in the business hub, calling the move "barbarous and rude". "The ill intentions of US politicians to support people who are anti-China and messing up Hong Kong have been clearly revealed," Beijing's Liaison Office in Hong Kong said in a statement. The US on Friday imposed sanctions on Hong Kong officials, including the pro-China leader of the government, accusing them of cooperating with Beijing's effort to undermine autonomy and crack down on freedom in the former British colony. The sanctions are the latest in a string of actions the Trump administration has taken targeting China as tensions between the two nations rise over trade, Covid-19 and other issues. President Donald Trump's offensive against China comes as he assigns full blame to Beijing for the coronavirus outbreak in the US, deflecting criticism of his own handling of the pandemic that threatens his re-election. The Treasury Department announced sanctions on Carrie Lam, the leader of the government in Hong Kong, and 10 other officials. The sanctions were authorised by an executive order that Mr Trump signed recently to levy penalties against China for its efforts to curtail anti-government protesters in Hong Kong. Hong Kong has long enjoyed civil liberties not seen in mainland China because it is governed under a "one country, two systems" principle in place since it reverted to Chinese rule in 1997. However, Beijing imposed a sweeping national security law on Hong Kong earlier this year, raising widespread concerns about the Chinese government cracking down on the anti-government protests. "The recent imposition of draconian national security legislation on Hong Kong has not only undermined Hong Kong's autonomy, it has also infringed on the rights of people in Hong Kong," the Treasury Department said in a statement. Treasury said the new law has allowed authorities in mainland China to operate with impunity in Hong Kong, has mandated "national security education" in Hong Kong schools, undermined the rule of law and laid the groundwork to censor individuals and outlets "deemed unfriendly" to China. The US said Lam, the chief executive of Hong Kong, is "directly responsible for implementing Beijing's policies of suppression of freedom and democratic processes." Last year, Lam pushed to allow citizens to be extradited to the mainland, setting off massive opposition demonstrations in Hong Kong, according to Treasury. Hong Kong Commerce Secretary Edward Yau called the sanctions "unreasonable and barbarous" and said they would harm US interests in the city, an Asian financial and shipping hub. One of the sanctioned officials, the head of the central government's liaison office in Hong Kong, said being included on the list shows that he has done what he should for his country. "I don't have a penny of assets abroad. Isn't it in vain to impose 'sanctions'? Of course, I can also send 100 US dollars to Mr. Trump for freezing," Luo Huining said in a statement on the office's website. Sen Ben Sasse, R-Neb, a member of the Senate intelligence committee, called Lam "Beijing's hatchet woman." He said she has worked with the Chinese Communist Party to kill Hong Kong's autonomy and gut the rule of law. "These cowards betrayed the freedom-loving people of Hong Kong and deserve to pay a steep price," he said. Also sanctioned was Chris Tang, the commissioner of the Hong Kong Police Force, for allegedly "coercing, arresting, detaining, or imprisoning individuals" under the new security law, and the former police commissioner, Stephen Lo. Friday's action blocks all property or other assets that the individuals have within US jurisdiction.