A U.S. company has announced a $400 million deal with the United States Department of Defense amid soaring demand for domestically mined rare earth elements that are critical for both civilian and military technologies.

July 7 (Reuters) - China's export restrictions on rare earths brought parts of the global auto supply chain to a halt and U.S. President Donald Trump to the negotiating table. But at home, they're a big headache for companies already struggling with a slow economy.

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