US Ambassador David Perdue stated that President Donald Trump issued a warning to Beijing against supporting Tehran during meetings at the White House on Thursday. Trump told Chinese President Xi Jinping that any form of direct or indirect assistance to Iran is "totally unacceptable," Perdue told CNBC on Friday. This ultimatum covers the transfer of intelligence, military equipment and components, and serves as a reinforcement of warnings the US has delivered to Beijing over the past few weeks.

Washington is treating the Iranian aid issue as a separate matter from its commitments to Taiwan. Perdue reported that Beijing has already "pulled some things down" in response to the warnings, though he did not specify which activities were curtailed. These diplomatic tensions follow reports that China delivered roughly 1,300 air shipments of dual-use drone and missile components to the Iranian Defense Ministry through June.