China said on Tuesday it would begin banning the export of some rare minerals to the United States, in an escalation of the tech war between the world’s two biggest powers. The move comes a day after the Biden administration tightened Chinese access to advanced American technology.

Sales of gallium, germanium, antimony and other materials to the United States would be halted immediately on national security grounds, China’s Ministry of Commerce said, citing the minerals’ use for military purposes. The export of graphite would also be subject to stricter review.

China produces almost all the world’s supply of critical minerals needed to make advanced technologies such as semiconductors. Beijing has been tightening its grip on the materials, also known as rare earths, in retaliation for U.S. export controls. In October, China began requiring its exporters to disclose, step by step, how the minerals would be used in Western supply chains.

On Monday, the Biden administration expanded its curbs on technology to China by prohibiting the sale of certain types of chips and machinery and adding more than 100 Chinese companies to a restricted-trade list. The move was the third significant action in the past three years in the Biden administration’s bid to prevent China from catching up to the United States in cutting-edge technologies.

China criticized the latest move by the United States, calling it “illegal.”

“Such practices seriously undermine the international economic and trade order, disrupt the stability of global production and the supply chain, and harms the interests of all countries,” said Lin Jian, a spokesman for China’s Ministry of Foreign Affairs.

Berry Wang contributed research.