London-based rights group Amnesty International said the law would give China sweeping new powers to name anyone in Hong Kong a criminal suspect under the law.
The Chinese embassy in Washington did not immediately respond to a request for comment.
Hong Kong's police force, already widely criticized for widespread violence against peaceful protesters and increasingly arbitrary arrests, has already set up a national security division to implement the law, according to Xinhua.
The special treatment of Hong Kong refers to what is offered by the Hong Kong Relations Act enacted by the U.S. Congress in 1992.
Secretary of State Mike Pompeo onsaid the US would stop exporting sensitive military items to Hong Kong, following his announcementthat Washington was imposing visa restrictions on current and former Chinese Communist Party members believed to be responsible for undermining Hong Kong's promised autonomy and traditional freedoms.
"This law risks seriously undermining the high degree of autonomy of Hong Kong and having a detrimental effect on the independence of the judiciary and the rule of law", said European Council President Charles Michel.
The exact details of the new law have yet to be released.
Last year, the Department of State approved approximately $2.4 million U.S. worth of controlled defence articles and services to Hong Kong government authorities, of which approximately $1.4 million USA worth was shipped, according State Department records.
Chan stated that it would be very hard to see Beijing withdraw the national security law, but local citizens must be united in voicing their opposition to the law.
Hong Kong was upended by seven straight months of protests a year ago, initially sparked by an eventually abandoned plan to allow extraditions to the mainland.
The announcements come at a time of intensified US rhetoric against Beijing as Trump campaigns for re-election in November.
Benedict Rogers, a co-founder of Hong Kong Watch, called for the appointment of a United Nations special envoy/rapporteur on Hong Kong, the passing of targeted sanctions against the perpetrators of human rights abuses, the formation of an global contact group to monitor the situation on the ground, and the coordination of an worldwide life-boat policy "to help Hongkongers in need of a lifeline".
Police have banned this year's July 1 rally on the anniversary of the 1997 handover, citing coronavirus restrictions.
China's enactment of a national security law for Hong Kong has drawn statements of deep concern and regret from overseas and a firm defense at home.
And Beijing will have jurisdiction over some cases, toppling the legal firewall that has existed between Hong Kong and the mainland's party-controlled courts.
Yoshihide Suga said China's move to pass national security legislation for Hong Kong, if confirmed, was "regrettable" and undermined credibility in the "one country, two systems" formula of governance.
"If (the reported enactment) is true, I have no choice but to say it will significantly affect President Xi Jinping's state visit to Japan", Kono said at a press conference. China had to make a decision as a matter of national security, he stressed.
Hong Kong's benchmark Hang Seng Index was up 0.2% in early afternoon trading Tuesday.
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Pakistan has always been plagued by Islamist militant violence but attacks have become less frequent in recent years. The Baluchistan Liberation Army has claimed responsibility for the attack in social media posts.