Kazakhstan has announced the discovery of its largest-ever deposit of rare earth metals, a significant development in the global race for critical raw materials. Located in the country’s central Karaganda region,

MP Materials , which owns the only U.S. rare earths mine, said on Thursday it has stopped shipping the critical minerals to China for processing after Beijing boosted import tariffs to 125% in response to U.

China has managed to hit the U.S. where it hurts the most in response to the Trump administration’s tariffs, with restrictions on global exports of certain rare-earth elements that the U.S. has little ability to produce or refine.