But China's National People's Congress, meeting in annual session to rubber stamp major policy passed by the ruling Communist Party, announced on Thursday it planned to adopt a law to "safeguard national security" by "establishing and improving the legal system and enforcement mechanisms" for Hong Kong.
On Thursday, State Department spokesperson Morgan Ortagus said: "Any effort to impose national security legislation that does not reflect the will of the people of Hong Kong would be highly destabilizing, and would be met with strong condemnation from the United States and the global community". It also provides that rights and freedoms, including those of the person, of the press, of assembly, of association and others, will be ensured by law in Hong Kong, and that the provisions of the two United Nations covenants on human rights (the International Covenant on Civil and Political Rights and International Covenant on Economic, Social and Cultural Rights) shall remain in force.
The Democratic Alliance for the Betterment and Progress of Hong Kong - the largest pro-establishment group in Hong Kong - said it welcomes and fully supports the proposal.
As long foreshadowed, China's Government is also looking to overhaul Hong Kong's separate education system, which pro-Beijing figures have attacked for being insufficiently patriotic. Police took down their information and issued penalty tickets as they said they breached Hong Kong's ban on gatherings of more than eight people, a restriction induced to contain the virus, local outlet Apple Daily reported.
The proposed legislation would permit Beijing to sidestep Hong Kong's own legislative body to limit protests or other activities that Beijing's authoritarian rulers consider subversive.
Chris Patten, Hong Kong's final British governor before the 1997 handover, said the proposal signalled a "comprehensive assault on the city's autonomy" and would be "hugely damaging".
Hong Kong's government said it would co-operate with Beijing to enact the law, adding it would not affect the city's freedoms.
Laws that harm democracy, human rights and Hong Kong's freedom under the guise of national security will increase societal instability and heighten risks for global citizens in the city, Taiwan's Mainland Affairs Council said in an emailed statement.
In reaction, the Hong Kong stock market closed down more than 5%.
"Any decision impinging on Hong Kong's autonomy and freedoms as guaranteed under the Sino British Joint Declaration and the Basic Law would inevitably impact our assessment of One Country, Two Systems and the status of the territory", Pompeo said. Hong Kong's value to China would drop considerably if its entrepreneurial people left and the city itself would no longer attract US investment.
The UK Government has yet to respond to the move by Beijing.
President Donald Trump has said the United States would react strongly if China followed through with its proposals, without giving details, the BBC reported. Some have described the proposed anti-sedition law as a "mark of desperation" after nearly a year of not being able to halt the protests.
"Many people have felt discouraged and helpless, while feeling there was nothing they could do except to watch Hong Kong die, then this national security law came along and our fighting spirit has returned!" said another post.
Instead, it has chosen what he called a "worse option" by proposing the NPC enact a national security law for the city.
Mass protests on the island past year were sparked by a bill that would have allowed extraditions to mainland China.
Beijing may also fear September's elections to Hong Kong's legislature.
Trump had only reluctantly signed the Hong Kong act, which was strongly opposed by Beijing, as he was negotiating a deal to end a trade war with China.
Activist Wong told DW News that Hong Kong's promise to cooperate with Beijing comes as "no surprise", calling Hong Kong a puppet state for the communist regime.
DW correspondent Phoebe Kong tweeted that the security law was "listed under annex 3 of basic law, bypassing scrutiny of the local legislature".