The House of Representatives in the United States unanimously passed the Hong Kong Human Rights and Democracy Act on Tuesday in a show of support for the on-going pro-democracy protests in the city, but the move drew strong opposition from Beijing.

Before the bill can become law, it must be passed by the Senate and approved by the president. Even if passed by the Senate, the president has the authority to veto the bill.

The passage of the bill came one day after a massive rally in Hong Kong on Monday night attended by what organizers estimated to be 200,000 people, who showed up in support of the legislation, despite the possibility of the bill threatening Hong Kong’s special status with the US if it becomes law. Hong Kong police claimed only 25,000 attended the rally.

The bill requires the US government to assess whether political developments in Hong Kong justify Washington continuing to treat Hong Kong as a separate trading entity from the rest of China.

It also requires the US president to identify and sanction people responsible for the erosion of autonomy and serious abuses of human rights in Hong Kong.

House Speaker Nancy Pelosi called the bill an important reminder of US support for human rights in the face of significant commercial interests in China, Associated Press reported.

Pelosi said the bravery of young protesters in Hong Kong stood in contrast to “the cowardly government that refuses to respect the rule of law” and the “one country, two systems” policy that was supposed to ensure a smooth political transition after the former British territory was returned to China in 1997.

Under US law, Hong Kong receives special treatment in matters of trade, customs, sanctions enforcement, law enforcement cooperation and more. China has benefited from this special status and used it to evade US export controls and sanctions, Pelosi and other lawmakers said.

“The House just sent a strong message to the people of Hong Kong: We stand with you in the fight for democracy and justice,” said Ben Ray Lujan, a House Democrat, AFP reported.

Republican House member Mario Diaz-Balart said the act ensures “that the special relationship with Hong Kong endures only as long as Hong Kong retains the autonomy and freedoms that justify that special relationship.”

The House also passed a resolution reaffirming the relationship between the US and Hong Kong, condemning Chinese interference in the region and voicing support for protesters.

Moreover, the House passed the Protect Hong Kong Act, which would bar commercial exports of military and crowd-control items such as teargas. These also need to be approved by the Senate.

Hong Kong protesters started lobbying for the passage of the bill in June, when the Hong Kong government proposed the now withdrawn fugitive ordinance that would enable China to extradite fugitives from the city.

The proposal triggered and led to turmoil in the city with an escalation of violence from both the police force and protesters.

The Chinese government expressed strong indignation and firm opposition against the passage of the bill on Wednesday, warning that China would take forceful counter-measures against the US decision, the Xinhua News Agency reported.

“Should the act eventually come into law, it will not only harm the interests of China and the China-US relations, but also severely undermine the interests of the United States,” Geng Shung, a foreign ministry spokesperson, said in a statement.

What Hong Kong faces is not the so-called human rights and democracy issues, but the issue of ending violence and chaos, he said, adding that US congressmen neglected the truth and only saw things in white and black.

The Office of the Commissioner of the Chinese Foreign Ministry in the Hong Kong SAR also expressed strong indignation, warning that playing Hong Kong as a card will get the US nowhere, according to a statement.

Some US politicians have openly endorsed anti-China troublemakers in Hong Kong, tested the red line of the “one country, two systems” principle, grossly interfered with Hong Kong’s affairs and China’s internal affairs as a whole, and trampled upon international law and basic norms governing international relations, the commissioner’s office said in a statement.

“We express strong indignation over and condemn such actions, which have again exposed the politicians’ gangster logic and hegemonic mindset,” it said.

The Hong Kong government expressed regret over the passage of the bill and reiterated that foreign legislatures should not interfere in any form in the SAR government’s internal affairs.

The statement said the Hong Kong government has been exercising “Hong Kong people administering Hong Kong” and a high degree of autonomy in strict accordance with the Basic Law.