Top US officials have accused China of betraying a trade truce reached earlier this year, escalating tensions between the two economic giants.
In an unusual, staged appearance, US Trade Representative Jamieson Greer and Treasury Secretary Scott Bessent blasted China's plans to curb exports of rare earths "economic coercion" and "a global supply chain power grab".
"If China wants to be an unreliable partner to the world, then the world will have to decouple," Bessent said.
At the same time, they left the door open to negotiation, questioning whether China would ultimately implement the export controls it announced last week.
"The scope and the scale is just unimaginable, and it cannot be implemented," Greer said on Wednesday of China's tightened export controls.
China processes around 90% of the world's rare earths and magnets - materials that are critical for advanced tech manufacturing and go into everything from cars to smartphones.
Its dominance of the sector is a key point of vulnerability in trade talks for the US, where many firms are rely on the materials.
