The Chinese government on Thursday announced that it was escalating its curbs on exports of rare earth metals, as Beijing claims broader jurisdiction over global manufacturing of semiconductors and other technology.

The new rules are the latest step by Beijing as it tries to tighten the reins on rare earths and exploit China’s dominance in the sector.

The changes could scramble the supply chains of some of the world’s biggest companies, including Nvidia and Apple. Rare earths are essential for the production of chips, which are used in everything from smartphones to automobiles and artificial intelligence systems.

China’s Ministry of Commerce said in a statement that the measures were needed to prevent rare earth metals from being used in technologies with possible military applications. But foreign governments and businesses have said that most rare earths are used for civilian purposes in devices like computer servers and gasoline-powered cars.

The rules bar the transfer from China of any equipment or information that would help other countries establish their own production of rare earths or rare earth magnets.

China mines and processes most of the world’s rare earths. Companies in the United States and Europe have been working to set up factories for the production of rare earth magnets, but it can take up to three years for such factories to ramp up to their maximum production capacity.