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 worldwide community".
Pro-democracy lawmakers protest against pro-Beijing lawmakers at the Legislative Council on May 22, 2020 in Hong Kong, China.
Mr Pompeo's intervention is likely to infuriate the Chinese government, whose relations with the U.S. have been strained recently by disputes over trade and the coronavirus pandemic. The Trump administration has foisted blame on China for failing to be sufficiently transparent at the outset of the deadly. virus.
Article 23 of Hong Kong's mini-constitution, the Basic Law, says the city must enact a law to prohibit "treason, secession, sedition (and) subversion" against the Chinese government.
The Chinese Communist Party is claiming the law is about "safeguarding national security", and so not fit for the LegCo but for the mainland National People's Congress, whose annual meeting starts Friday.
The practice of "one country, two systems" has achieved unprecedented success in Hong Kong, according to an explanatory document delivered by Wang, state-run Xinhua news agency reported.
"International NGOs operating in Hong Kong will not be safe".
It is also a way for China to send a message to the USA, which is debating whether to continue granting Hong Kong special trade status under the Hong Kong Human Rights and Democracy Act, passed past year to pressure Beijing into respecting the city's rights.
In his statement, Mr Pompeo said any decision to impinge on Hong Kong's autonomy and freedoms would "inevitably impact our assessment" of the territory's status.
The US is now considering whether to extend Hong Kong's preferential trading and investment privileges.
Against all expectation, they won: The proposed law allowing Hong Kongers to be extradited to China was shelved, and pro-democracy candidates won overwhelmingly in the city's elections for community councilors.
President Donald Trump has said the USA would react strongly if China followed through with its proposals, without giving details, the BBC reported.
Young, violent protesters who threw petrol bombs during skirmishes with police and who were derided by officials and Chinese state media as "terrorists" could also be covered in the laws.
"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.
He nevertheless cautioned of the risks of the United States revoking the city's trading status, while acknowledging that many in Hong Kong were angry and would back the move. Up to now, the worst charge most arrested protesters have faced has been for rioting.
Opposition legislator Dennis Kwok also warned reporters yesterday that the law would be the "end of one country, two systems".
On internet threads and chat apps used by the pro-democracy movement, there were calls to resume the protests of a year ago that were largely subdued in recent months because of coronavirus restrictions.
"More than 20 years after Hong Kong's return, relevant laws are yet to materialize due to the sabotage and obstruction by those trying to sow trouble in Hong Kong and China at large, as well as external hostile forces", Wang said.
Hong Kong was under British control for more than 150 years up to 1997.
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.
The British and Chinese governments signed a treaty - the Sino-British Joint Declaration - that agreed Hong Kong would have "a high degree of autonomy, except in foreign and defence affairs", for 50 years.
DW correspondent Phoebe Kong tweeted that the security law was "listed under annex 3 of basic law, bypassing scrutiny of the local legislature".