Ahead of a Trump-Xi summit, Washington widens its crackdown on secretive oil and chemical trade between Beijing and Tehran.

The president made the claim, which Beijing has yet to confirm, amid anger in China that its vessels could be caught up in a U.S. blockade targeting Iranian ports.

Beijing urged Iran to accept a ceasefire, but it hasn’t agreed to act as a guarantor of the deal in America’s messy war.

Private Chinese technology companies — some with ties to the military — are marketing detailed intelligence on movements of U.S. forces in Iran, even as Beijing seeks to keep its distance.