The US says it’ll crack down on countries doing business with Iran. Who’s buying Iranian oil?

New York — US Treasury Secretary Scott Bessent on Monday vowed an “economic D-Day” for countries that buy oil from Iran. Experts say that means one country in particular: China.
Bessent didn’t name China on Monday, but he left little room for doubt.

“We find that the best way to engage with countries is through quiet diplomacy, and we are level-setting with every country to tell them our expectations,” Bessent said on Monday. “We know who they are. They know who they are.”

But while Bessent’s threat could put China front and center, the repercussions could reach across the world – even for American consumers, who could find their own energy costs rising as a result.

Tehran likely shipped $3.9 and $4.2 billion worth of oil in September 2025, one analysis found; China, the world’s largest energy consumer, buys the vast majority.

“Chinese purchases account for roughly 90 percent of Iran’s exported oil, providing tens of billions of dollars in annual revenue that supports Iran’s government budget and military activities,” the U.S.-China Economic and Security Review Commission said earlier this year.

Monday’s announcement was a “warning shot,” Bessent said. While some entities and individuals were sanctioned, he did not announce broad measures aimed at any specific nations.