China warned countries negotiating with the U.S. that they will face retaliation if they strike tariff deals that harm Beijing, further complicating trade talks around the world.

“China firmly opposes any party reaching a deal at the expense of China’s interests,” China’s Commerce Ministry said in a statement. “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.”