The United States and China imposed fresh tariffs on each other’s goods on Monday as the world’s biggest economies showed no signs of backing down from an increasingly bitter trade dispute that is expected to knock global economic growth.

Soon after the new duties went into effect, China accused the U.S. of engaging in “trade bullyism” and said it was intimidating other countries to submit to its will, the official Xinhua news agency said, reiterating China’s willingness to fight if necessary.

But Beijing also said it was willing to restart trade negotiations with the United States if the talks are “based on mutual respect and equality,” Xinhua said, citing a white paper on the dispute published by China’s State Council.