The US House of Representatives passed a bill on Tuesday sought by pro-democracy protesters in Hong Kong that aims to defend civil rights in the semi-autonomous territory.
The Hong Kong Human Rights and Democracy Act, which will now move to the Senate before it can become law, has drawn rare bipartisan support in a polarised Congress.
The law would end the Hong Kong-US special trading status unless the State Department certifies annually that city authorities are respecting human rights and the rule of law.
The act will now move to a similar vote in the Senate before it can become law.
"Today we're simply urging the Chinese president and the Hong Kong Chief Executive, Carrie Lam, to faithfully honor the Government's promises" that Hong Kong's rights and autonomy would be protected, Republican Representative Chris Smith, prime sponsor of the bill, said on Tuesday on the House floor.
"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.