China is threatening “strong countermeasures” if the U.S. Congress moves forward and enacts legislation supporting the ongoing protests in Hong Kong, a move that would further endanger the relationship between the two countries that are already embroiled in a trade war.

Beijing made the threat after the U.S. House of Representatives passed measures backing the pro-democracy movement in Hong Kong, which is a former British territory handed back over to China in 1997 with the promise that the way of life in Hong Kong would remain unchanged for 50 years.

The protests have been going on for four months now, beginning with a now-rescinded extradition law where citizens of Hong Kong could be shipped off to China to face trial for alleged crimes.

Among the measures passed is the Hong Kong Human Rights and Democracy Act, which would make the United States’ special trading status with Hong Kong have to undergo a yearly review. It also allows for sanctions against Hong Kong officials who are responsible  for not following through with “fundamental freedoms and autonomy.”

The legislation also must pass the GOP-controlled Senate and be signed by U.S. President Donald Trump before it becomes law, and it has strong bipartisan support. The measures passed through the Democrat-controlled House by unanimous vote, so it seems likely to get through the Senate.

China’s Ministry of Foreign Affairs, Geng Shuang, warned the U.S. lawmakers, saying they should stop meddling in the country’s internal affairs “before falling off the edge of the cliff.”

The measure “fully exposes the shocking hypocrisy of some in the U.S. on human rights and democracy and their malicious intention to undermine Hong Kong’s prosperity and stability to contain China’s development,” Geng said in a statement.

Trump and Chinese President Xi Jinping have mostly been able to tamp down outrage over what’s going on in Hong Kong and keep things from boiling over into the ongoing trade negotiations. The two sides came to a bit of a ceasefire last week when Trump agreed to hold off on upping tariffs on $250 billion worth of Chinese imports from 25% to 30%. Beijing, in turn, agreed to buy more U.S. agricultural products to help out American farmers who have been devastated by the trade war.

“I don’t think this will undermine the prospect of signing a partial deal next month,” Chinese cabinet member Wwang Huiyao said. “The Hong Kong bill is not a done deal and there is still room for redemption.”

A spokesman for Hong Kong’s government also “expressed regret” over the measures as Chief Executive Carrie Lam prepared to give her annual policy address.

Tens of thousands of protesters gathered this week urging the passage of the measures, many of whom were waving the U.S. flag in support.

New Jersey Republican Rep. Chris Smith sponsored the Hong Kong measures, predicting the Senate will pass it while also dismissing the threats from China.

“Retaliation, that’s all they ever talk,” Smith said on Bloomberg TV. “They try to browbeat and cower people, countries, presidents, prime ministers and the like all over in order to get them to back off. We believe that human rights are so elemental, and so in need of protection. And that’s why the students and the young people are out in the streets in Hong Kong virtually every day.”