"If China does not withdraw its 34 percent increase above their already long term trading abuses by tomorrow, April 8th, 2025, the United States will impose ADDITIONAL Tariffs on China of 50 percent, effective April 9th," Trump said in a Truth Social post.

Beijing has issued countermeasures after Trump announced another sharp tariff hike on goods from the world's second biggest economy last week.

Since returning to the presidency, Trump has imposed 20 percent added duties on Chinese imports over its alleged role in the fentanyl supply chain.

A fresh 34 percent levy on the country's products is due to kick in Wednesday, bringing the added rate this year to 54 percent.

It is not immediately clear how Trump's new threat factors into this calculation.

China's response included export controls on rare earth elements, and Beijing plans for its own 34 percent tariff on US goods, stacking atop existing Chinese levies set to begin April 10.

Trump took aim at Beijing's economic practices on social media Monday, criticizing its "non-monetary tariffs" and "illegal subsidization of companies."

He added that "all talks with China concerning their requested meetings with us will be terminated."

But "negotiations with other countries, which have also requested meetings, will begin taking place immediately," Trump wrote on his Truth Social platform.