The bill mandates sanctions on Chinese and Hong Kong officials who carry out human rights abuses and require an annual review of the favorable trade status that Washington grants Hong Kong.
China's government has promised unspecified countermeasures in response.
Congress approved the Hong Kong Human Rights and Democracy Act even as U.S. and Chinese officials try to nail down a "phase one" trade deal amid an ongoing tariff battle. A Chinese Commerce Ministry official dismissed speculation that trade talks would falter because of the legislation as "rumors" on Thursday.
Ministry spokesman Gao Feng said he had no new information to release. But he said China was committed to working toward an agreement.
"China is willing to address core concerns together with the U.S. on a basis of equality and mutual respect, and to work to conclude our discussions on the first phase" of a trade deal, Gao told reporters at a weekly briefing.
Republican Sen. Marco Rubio of Florida said in introducing the bill that it would send a message of support to the Hong Kong people who have protested for basic freedoms in the face of Chinese government oppression.
The Senate passed the resolution Tuesday, and the House approved it Wednesday. Rep. Thomas Massie, R-Ky., was the only no vote.
The Associated Press contributed to this report.