Boeing (BA) shares are falling in premarket trading Tuesday after Beijing reportedly told its airlines not to take more deliveries of the American company's jets, as the trade war between the U.S. and China heats up.

Beijing also "asked that Chinese carriers halt any purchases of aircraft-related equipment and parts from U.S. companies," Bloomberg reported, citing people famil๊i༒ar with the matter.

China last Friday hiked its tariffs on imports from America to 125%, in retaliation for the 145% duties its goods face from the U.S. The report sai✨d the 125% tariffs on U.S. imports would "have more than doubled the cost of U.S.-made aircraft and parts, making it impractical for Chinese airlines to accept Boeing planeꦕs."

Boeing s🌼hares, which have fallen 10% year-to-date entering Tuesday,𒁃 were down a further 3% in premarket trading.

Boeing didn't immediately respond to a request for comment.