The White House on Tuesday featured a mining company partially owned by a Chinese mining conglomerate at an event dedicated to strengthening the domestic supply chain.

President Joe Biden announced at the event that the Pentagon would award $35 million to the Las Vegas-based MP Materials in an effort to boost U.S. rare mineral production. But MP Materials has arguably allowed China to tighten its grip on the world’s rare earth minerals supply chain. Shenghe Resources Holding, which is partially owned by the Chinese government, owns 8 percent of the company. Shenge spearheaded the deal in 2017 to help MP Materials purchase a mine at Mountain Pass, Calif., out of bankruptcy. The Chinese company is also MP Materials’s largest customer, accounting for nearly all of its $100 million annual revenue.

MP Materials’s links to China have long concerned American officials. The Department of Energy warned its scientists in 2020 not to collaborate with MP Materials executives because of China’s links to the company, Reuters reported.