China threatened to retaliate after President Donald Trump signed two bills into law in support of Hong Kong protesters.
"China firmly opposes Hong Kong Act. We have made stern representations & strong protests to U.S.," Geng Shuang, a spokesman for the Chinese Foreign Ministry, said in a briefing Friday. "It is a stark hegemonic practice & a severe interference in Hong Kong affairs, which are China's internal affairs. China will take strong counter-measures."
Geng did not specify what those counter-measures would be, however.
Trump signed a bill into law on Wednesday that requires the State Department to certify annually that Hong Kong has sufficient autonomy to retain special U.S. trading consideration, which helps Hong Kong's economy. The second measure signed by Trump bars the sale of tear gas and rubber bullets to the Hong Kong police.
Hong Kong has been in turmoil for months after protests were sparked by a bill that would have permitted extradition to mainland China. Since then, the protests have transformed into broader anti-government demonstrations.
The protests, along with Trump's decision to sign those measures, come as China and the U.S. try to work out a trade deal. Both sides have slapped tariffs on billions of dollars worth of their goods since last year.
Investors fear the signing of these measures could complicate negotiations as a key Dec. 15 deadline approaches. If a deal is not reached by then, an additional round of U.S. tariffs on Chinese products would take effect.
Neither the White House nor the U.S. Trade Representative's office responded to CNBC's request for comment on the Chinese spokesman's reported remarks.
—CNBC's Yun Li and Kevin Breuninger contributed to this report.