Jensen Huang, the chipmaker’s chief executive, is trying to balance his company’s interests as the United States and China compete for supremacy in artificial intelligence.

Beijing will now require government licenses for any effort to transfer abroad the technologies crucial for producing inexpensive electric cars.

The continent wants to reduce the risks of depending so heavily on China for the valuable minerals. The question is how.

Dust and groundwater contaminated with heavy metals and radioactive chemicals pose a health threat that the authorities have been trying to address for years.

Low environmental standards helped China become the world’s low-cost producer of rare earths, but Beijing was also focused on helping the industry.

The deal involves loosening exports of rare earths to the United States and the lifting of some restrictions on U.S. goods to China, China’s Ministry of Commerce said.