Deputy police commissioner Edwina Lau Chi-wai - one of four Hong Kong and mainland officials hit by the latest round of sanctions by the United States - says the US government's attempt to use the "so-called sanctions" to strike a blow at the police force's work on national security is futile.

The US Department of State yesterday slapped another rounds of sanctions on four more Hong Kong and mainland officials in connection with the implementation of the Beijing-imposed national security law on Hong Kong.

Secretary of State Michael Pompeo said in the announcement that those on the list will be barred from traveling to the United States and their assets within the jurisdiction of the US or in the possession or control of US persons will be blocked.

"These actions underscore US resolve to hold accountable key figures that are actively eviscerating the freedoms of the people of Hong Kong and undermining Hong Kong's autonomy," Pompeo said.

Beijing denounced the latest round of sanctions.

Foreign Ministry spokesman Wang Wenbin said China firmly opposed and condemned the so-called "sanctions" by the US.

He said the US intervention in Hong Kong and China affairs violates international law and basic norms of governing international relations.

"No foreign forces have the right to intervene. China urges the US to stop meddling in Hong Kong's affairs and immediately revoke the so-called sanctions. Do not walk further along the wrong path," Wang said.

Apart from Lau, who heads the police's national security department, senior superintendent Steve Li Kwai-wah from the department is also named.

In response, Lau said she is not afraid and will continue to be determined and concentrate on safeguarding Hong Kong and national security. Lau said it is her pride and honor to lead the department.

Li described the sanctions as unfair and said his determination to protect and enforce the law will not be shaken.

"Safeguarding national security is the natural responsibility of any police officers across the globe. Serving the police force and defending Hong Kong is my lifetime responsibility and honor," Li added.

The other two are deputy director of the Office for Safeguarding National Security, Li Jiangzhou, and the deputy director of the Hong Kong & Macao Affairs Office, Deng Zhonghua.

"The HKMAO - one of the central government's primary offices on Hong Kong policy - has taken several actions to interfere in Hong Kong affairs and crack down on protesters," Pompeo said.

Acting Chief Executive Matthew Cheung Kin-chung said the sanctions are absolutely unreasonable and unacceptable.

"My comment is very simple, that this action is entirely unacceptable, outrageous, and I would use the word barbaric - interference in Hong Kong's internal affairs," Cheung said.

He added that it is incumbent on SARofficials and Hongkongers to safeguard national security and the government will not be intimidated by the sanction.

The US previously imposed sanctions on 11 Hong Kong and mainland officials on August 7 for undermining Hong Kong's autonomy, including Chief Executive Carrie Lam Cheng Yuet-ngor, Commissioner of Police Chris Tang Ping-keung and his predecessor Stephen Lo Wai-chung.

A spokesman said last night the government is not intimidated by "such despicable behavior" and will resolutely continue to implement the law.

"The repeated blatant and barbaric interference in internal affairs by the US is another vivid example of bullying against the central people's government and SAR government officials."

The four sanctioned are, from left, Deng Zhonghua, Li Jiangzhou, Steve Li and Edwina Lau.

Security police boss unfazed by sanctions