China has expanded its use of critical minerals as a trade weapon with curbs on exports of rare earths, threatening to shake-up the global supply of key materials used widely in high-tech manufacturing from electric vehicles to weaponry.

The Chinese government said it would match President Trump’s tariff, and also barred a group of American companies from doing business in China.

Communication between Washington and Beijing is at a standstill, raising the prospects of a long cycle of tariff retaliation. “Trump and Xi are locked in a paradox of pressure and pride.”