#DinnerWithTrump The director of Tesla, Elon Musk, told investors last month that Chinese officials had requested guarantees that the rare earth magnets used in the company's robotic arms would not be used in military hardware. “That is an example of a challenge there. I am sure we will overcome these issues,” he said.

The permanent magnets made from rare earths are found in fighter jets like Lockheed's F-35. Short-term shortages could disrupt production lines, and experts predict that the new controls will accelerate long-term efforts in the West to build alternative supply chains.

Evan Scott, chief financial officer of Lockheed, told investors this week that the company had enough rare earth material for the rest of the year. He added that he expected U.S. authorities to prioritize Lockheed's needs “given the importance of our programs.”