The US has imposed sanctions on Hong Kong officials, including the pro-China leader of the government, Carrie Lam, accusing them of roles in squashing freedom in the former British colony.

The Treasury Department 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 disputes and coronavirus.

An executive order that President Donald Trump signed recently to levy penalties against China for its efforts to curtail anti-government protesters in Hong Kong authorised the sanctions.

The action blocks all property or other assets that the individuals have within US jurisdiction.

Hong Kong has long enjoyed civil liberties not seen elsewhere in mainland China because it is governed under a “one country, two systems” principle in place since it reverted to Chinese rule in 1997.

But 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.

It 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 Ms Lam is “directly responsible for implementing Beijing’s policies of suppression of freedom and democratic processes”.

Last year, she pushed to allow citizens to be extradited to the mainland, setting off massive opposition demonstrations in Hong Kong, according to Treasury.

Also sanctioned is 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.

The remaining officials sanctioned were John Lee Ka-chiu, secretary for security in Hong Kong who has introduced a new police unit that will have intelligence gathering and investigative abilities to enforce the new security law; Teresa Cheng, secretary of justice; Erick Tsang, secretary of constitutional and mainland affairs; Xia Baolong, director of the Hong Kong and Macao Affairs Office and its deputy director Zhang Xiaoming; Luo Huining, director of the Hong Kong liaison office; Zheng Yanxiong, director of a new office for safeguarding national security in Hong Kong, and Eric Chan, secretary general of the committee for safeguarding national security.

“The Chinese Communist Party has made clear that Hong Kong will never again enjoy the high degree of autonomy that Beijing itself promised to the Hong Kong people and the United Kingdom for 50 years,” Secretary of State Mike Pompeo said in a statement.

“President Trump has made clear that the United States will therefore treat Hong Kong as ‘one country, one system’ and take action against individuals who have crushed the Hong Kong people’s freedoms.”