HONG KONG - Hong Kong's justice secretary said on Sunday that a mainland Chinese law to counter foreign sanctions could also be adopted in the China-ruled city by writing it into Hong Kong's mini-constitution, pending a decision by the Chinese parliament.

Justice Secretary Teresa Cheng's comments are the strongest official indication so far that Hong Kong would embrace the mainland law, passed in June to counter foreign sanctions as the U.S. and EU step up pressure over trade, technology, Hong Kong and Xinjiang.

Under the law, individuals or entities involved in making or implementing discriminatory measures against Chinese citizens or entities could be put on an anti-sanctions list by relevant departments in the Chinese government.

Cheng wrote in an official blog entry that the "most natural and appropriate way" to introduce the anti-sanctions law into Hong Kong would be to add it to an annex of the Basic Law, or Hong Kong's mini-constitution.

She added that such a move needed first to be approved by the highest organ of China's parliament, the National People's Congress. Local media have reported that a decision would likely be made during a meeting in Beijing on Aug 17-20.

Critics have warned that the anti-foreign sanctions law could undermine Hong Kong's reputation as a global financial hub, and tarnish sentiment among foreign firms.

Hong Kong, a former British colony, returned to Chinese sovereignty in 1997 with a guarantee of a high degree of autonomy and freedoms.

The U.S. government issued a business advisory last month warning firms that they are subject to the territory's laws, including a China-imposed national security law, under which foreign nationals, including one U.S. citizen, have been arrested.

The U.S. government has imposed several rounds of sanctions on Hong Kong and Chinese officials over Beijing's crackdown on the city's freedoms under the sweeping security legislation.

Without naming the United States directly, Cheng wrote that countermeasures were acceptable.

"Unilateral coercive measures are without a doubt at odds with the principle of non-intervention, unbecoming of any civilised nation," she wrote.

"In the face of international illegal acts, a State is justified in deploying any countermeasures as a response."

Under China's anti-foreign sanctions law, individuals could be denied entry into China or be expelled. Their assets within China may be seized or frozen. They could also be restricted from doing business with entities or people within China.

(Reporting by James Pomfret; Editing by Edmund Klamann) ((james.pomfret@thomsonreuters.com; +852-28436390; Reuters Messaging: james.pomfret.thomsonreuters.com@reuters.net))