Frank Eckard, CEO of a German magnet maker, has been fielding a flood of calls in recent weeks. Exasperated automakers and parts suppliers have been desperate to find alternative sources of magnets, which are in short supply due to Chinese export curbs.

Some told Eckard their factories could be idled by mid-July without backup magnet supplies. “The whole car industry is in full panic,” said Eckard, CEO of Magnosphere, based in Troisdorf, Germany. “They are willing to pay any price.”

Car executives have once again been driven into their war rooms, concerned that China’s tight export controls on rare-earth magnets — crucially needed to make cars — could cripple production.

U.S. President Donald Trump said June 6 that Chinese President Xi Jinping agreed to let rare earths minerals and magnets flow to the United States. A U.S. trade team is scheduled to meet Chinese counterparts for talks in London on June 9.

The industry worries that the rare-earths situation could cascade into the third massive supply chain shock in five years.