The deal would see the Defense Department take a 15% stake in MP Materials and spend billions of dollars investing in the company and purchasing its output.

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.

MP Materials has announced plans to expand rare earth mining and processing operations as Washington seeks to end its dependence on Chinese supplies.