China has ordered its airlines not to take further deliveries of Boeing jets in response to the U.S. decision to impose 145% tariffs on Chinese goods, Bloomberg News reported on Tuesday, citing people familiar with the matter.

China has managed to hit the U.S. where it hurts the most in response to the Trump administration’s tariffs, with restrictions on global exports of certain rare-earth elements that the U.S. has little ability to produce or refine.

Beijing has a virtual monopoly on rare earth minerals—the materials that power everything from military planes to your electric toothbrush.