China has warned countries against striking trade deals with the U.S. at its expense to secure relief from President Donald Trump’s tariffs, threatening retaliation against those that do.

As the trade war between the world’s two largest economies escalates, the Chinese Ministry of Commerce promised to retaliate against any country that reaches an agreement with the U.S. that limits its trade with China. The U.S. tariffs against other countries are economic bullying, the ministry said in a statement attributed to an unnamed spokesperson, translated by the Associated Press.

“China firmly opposes any party reaching a deal at the expense of China’s interests,” the Chinese government said Monday.

“If this happens, China will never accept it and will resolutely take countermeasures in a reciprocal manner. China is determined and capable of safeguarding its own rights and interests.”