US Threat of Maximum Iran Sanctions Tests Trump's Detente With China

The administration of US President Donald Trump has stated its intention to sever every economic lifeline sustaining Iran through what officials describe as the toughest sanctions campaign in history. If carried out, this threat places China—Iran's largest trade partner—directly in the crosshairs of upcoming US measures set to be announced on Monday.

While the Trump administration has not yet provided specific details regarding its so-called “economic D-Day,” US officials have emphasized that Iran's trade partners are being targeted. In a Sunday op-ed in the Financial Times, US Treasury Secretary Scott Bessent warned nations wary of cutting ties with Iran not to underestimate the costs of testing Washington.

According to Brett Erickson, a sanctions expert and managing principal of Obsidian Risk Advisors, the willingness of the Trump administration to target China will demonstrate its true resolve for a prolonged economic offensive against Tehran. Without including China, any US pressure campaign would remain strictly limited due to the immense economic ties between Beijing and Tehran.

Data from the US-China Economic and Security Review Commission shows that China reported $9.96bn in bilateral trade with Iran in 2025, alongside $31.2bn in Iranian oil shipments. Furthermore, US Treasury Department figures indicate that Chinese purchases account for approximately 90 percent of Iran's total oil sales.

Up to this point, Washington has largely avoided targeting major Chinese financial institutions, focusing instead on a few smaller entities such as Hengli Petrochemical (Dalian) Refinery, four firms in Hong Kong, and six shipping lines based in China and Hong Kong.

Jennifer Kavanagh, a senior fellow at Defense Priorities, noted that while cutting Chinese ties is vital for intensifying pressure on Iran, doing so risks severe retaliation from Beijing. Meanwhile, China's Ministry of Foreign Affairs stated that Beijing remains committed to peace talks, and Iran has warned that any country supporting the US measures will be treated as an enemy.

The upcoming diplomatic dynamic is further complicated by an upcoming summit between US President Donald Trump and Chinese leader Xi Jinping scheduled for September 24 at the White House. Analysts suggest both nations will likely attempt to keep the Iran dispute from completely derailing the broader bilateral agenda, though Beijing is expected to respond to any material actions against its corporate interests.