Negotiations on ending the longstanding trade war could face a tougher path this month following the flareup over Hong Kong.
The protesters' demands include universal suffrage, an investigation into alleged police brutality in handling the protests, and an end to Beijing's perceived efforts to undermine democratic freedoms promised when the former British colony was handed back to China in 1997.
A landslide victory by pro-democracy candidates in recent district council elections showed the need for the government to address protester grievances, she added. "Just stay with Hong Kong, free Hong Kong and please boycott China".
"The government wants us to desert the front-liners and young protesters, but we will stick with them, " rally organiser Tam Kwok-sun, 64, said to loud cheers from the crowd.
"Hong Kong's human rights and freedom are protected under the Basic Law", Lam said, referring to the territory's mini-constitution.
The Hong Kong Human Rights and Democracy Act, which the Senate and House passed, puts the special treatment that Hong Kong enjoys under U.S. law under tighter scrutiny linked to the extent of Hong Kong's autonomy from Beijing.
This came days after President Trump signed several new bills into law, which will support protesters' months-long demonstrations. "We have freedom of the press, freedom of assembly, freedom of religion and in many other areas".
Earlier on Monday, Lam described the HKHRDA as clear interference by Washington in Hong Kong's internal affairs, echoing the stance of Beijing.
After President Donald Trump signed into law the Hong Kong Human Rights and Democracy Act last week, Beijing warned that it would "take strong counter-measures in response to the U.S. behavior that interferes in China's internal affairs and undermines China's interests".
A spokeswoman for China's foreign ministry said on Monday, Beijing would also slap sanctions against certain American NGOs, including Human Rights Watch.
Among the groups to be subject to the unspecified sanctions, the National Endowment for Democracy receives funding directly from Congress, while others generally draw their running costs from a mixture of private and public grants.
The airline says that passengers holding confirmed bookings on flights to/from Vancouver after February 10 can get a full refund, free change of travel date, free change to any destination operated by Hong Kong Airlines (fare and taxes difference may apply) or free transfer to other partner carriers to be arranged by Hong Kong Airlines, subject to seat availability.
Police had issued permits called "letters of no objection" for all three events, including a morning rally for children and seniors which went ahead without incident, and the post urged people to remain peaceful.
In response, China's government announced Monday it is banning Navy ship visits to Hong Kong, and placing new curbs on the activities of several USA private rights groups.
Pacific Fleet informed Insider that China has actually been rejecting port call requests for months now, with 7 denials in the past six months.
"Beijing's tantrum doesn't change anything", said US Senator Ben Sasse.