The United States Senate unanimously passed a bill Tuesday that would require an annual review of the special treatment Hong Kong receives under US law following almost six months of unrest in the Asian financial hub.
The vote will be seen as boost for Hong Kong's pro-democracy protesters, and a challenge to the Chinese government at a time of strained US-China relations, marked by a protracted trade war and geopolitical jostling.
The US government treats semi-autonomous Hong Kong, which has its own legal and political systems, differently from the Chinese mainland when it comes to trade and export controls.
The Hong Kong Human Rights and Democracy Act -- if it becomes law -- will demand greater scrutiny of the city's special status.
The bill also lays out a process for the President to impose sanctions and travel restrictions on those who are found to be knowingly responsible for threatened or carried out arbitrary detention, torture, forced confession of any individual in Hong Kong, or other violations of internationally recognized human rights in the former British colony.
Under the bill, the President can also impose sanctions on those who violate the 1997 Sino-British Joint Declaration -- the agreement under which Britain handed Hong Kong back to China, and which sets the terms of the city's autonomy. For months, protesters have accused China of infringing on the agreement by encroaching on Hong Kong's protected freedoms.
The democracy bill has received broad bipartisan support and will now go to the House of Representatives, which passed a slightly different version of the bill last month. Then, it will head to the White House for President Donald Trump to review.
The vote was met with triumph in the Senate but anger and condemnation from China. In a statement, the Chinese Ministry of Foreign Affairs said the bill "neglects facts and truth, applies double standards and blatantly interferes in Hong Kong affairs and China's other internal affairs."
It also claimed that the issue at hand was not about democracy, but about stopping the "chaos" wreaked by "violent criminals."
"China will have to take strong countermeasures to defend our national sovereignty, security and development interests if the US insists on making the wrong decisions," the statement said, urging the US to "stop interfering."
A separate statement from the Hong Kong government stressed that the city's constitution safeguarded human rights and freedom, and that the Senate bill would "harm the relations and common interests between Hong Kong and the US."
Meanwhile, many Congress members voiced their support for the bill and for the Hong Kong protesters. Sen. Chuck Schumer of New York, the top Democrat in the Senate, called the unanimous vote "a resounding message to the Chinese Communist Party and President Xi that the United States stands with the democratic protesters in Hong Kong."
Secretary of State Mike Pompeo, who has been more tight-lipped on Hong Kong, said on Tuesday that the US was watching the escalating violence in the city "closely," and urged a peaceful resolution to the crisis.
There is one notable voice missing -- Trump has largely refrained from entering into the fray as he works through stalled trade talks with China.
In June, as the protests kicked off, Trump promised Chinese President Xi Jinping in a phone call that the US would remain quiet on the protests while trade talks continued, according to sources familiar with the call.
Trump's pledge is a dramatic departure from decades of US support for human rights in China -- and is all the more striking as Congress has overwhelmingly sided with the protesters.
The bill could also complicate the trade talks if it places pressure on the White House to sanction China for its role and actions in the protests.
The turmoil in Hong Kong began as peaceful mass marches against a now-withdrawn China extradition bill. Protesters feared Beijing would use the bill to extract Hong Kongers for political reasons to face justice in mainland China's opaque legal system.
As the stand-off with the government stretched on, peaceful mass marches increasingly descended into violence -- and the movement quickly expanded to include demands for an independent inquiry into alleged police brutality and for universal suffrage.
Violence on both sides has steadily ramped up over the past few months. It escalated dramatically in the past two weeks, with the death of 22-year-old student near a protest and this week's siege at Hong Kong Polytechnic University.
A small group of protesters is still barricaded inside the university, and police have surrounded the campus for days, arresting those who come out.
Haley Byrd contributed reporting.