China announced Tuesday it is banning exports to the United States of gallium, germanium, antimony and other key high-tech materials with potential military applications, as a general principle, lashing back at U.

China has banned exports of some rare minerals to the United States as tensions over trade heat up after the U.S. issued new restrictions on exports of certain semiconductor chips and equipment to China earlier this week.

Over the past several months, China has started tightening control over its supply of rare materials. It started limiting the export of antimony — a mineral used for chipmaking