How U.S. Secondary Sanctions on Iran Could Pressure China
The latest U.S. pressure campaign against Iran is aimed not only at Tehran. It also targets the financial routes, oil buyers and trading partners that help Iran keep earning revenue. That makes China the most important test of whether Washington can tighten the screws without triggering a wider confrontation.
The pressure extends beyond Iran
Primary sanctions generally prohibit U.S. companies, banks and citizens from doing business with a designated person or country. Secondary sanctions go further: they threaten foreign companies or financial institutions with penalties if they continue certain transactions with the sanctioned party.
A Chinese bank, shipping firm or refinery may have no direct U.S. connection. But if it handles a prohibited Iranian oil transaction, Washington could restrict its access to the U.S. financial system or bar it from dealing with American institutions. That threat often causes companies to withdraw even before the U.S. government formally lists them.
The Treasury Department has used this model across Iran’s oil, shipping and financial sectors. Its recent actions have also focused on cryptocurrency exchanges and networks accused of helping Iran’s Islamic Revolutionary Guard Corps move money outside conventional banking channels. Treasury says those measures are part of a broader policy of maximum economic pressure. (home.treasury.gov)
Why China matters so much
China has remained Iran’s most significant economic outlet, particularly for oil. Reuters reported that Beijing buys more than 80% of Iran’s shipped oil, based on 2025 data from Kpler. If Chinese purchasers, insurers, ports or banks retreat, Iran could lose much of the commercial infrastructure that turns oil into usable foreign currency. (ca.investing.com)
That does not mean China must accept Washington’s demands. Beijing has repeatedly rejected what it calls unilateral sanctions lacking authorization from the United Nations Security Council. China’s Foreign Ministry has also said it wants the United States and Iran to implement their existing memorandum of understanding and continue negotiations. (mfa.gov.cn)
The dispute therefore has two layers. The United States is asserting its ability to regulate access to the dollar-centered financial system. China is defending its companies’ commercial ties and challenging the legal and political reach of U.S. sanctions.
Diplomacy is still running in parallel
The sanctions threat has not eliminated diplomacy. Egyptian and Iranian officials have discussed efforts to bring Tehran and Washington back to negotiations, while Oman remains involved in contacts concerning the conflict and the Strait of Hormuz, according to the Associated Press. Iran’s security officials have issued threats against regional states that assist the pressure campaign, raising the risk that economic measures could produce military or shipping-related retaliation. (apnews.com)
The key uncertainty is implementation. A promised sanctions package can change through exemptions, wind-down periods or selective enforcement. Until the U.S. Treasury publishes the final designations and rules, it is not possible to know which Chinese companies or sectors would face the greatest exposure.
What is clear is the strategic choice facing Beijing: preserve access to Iranian energy and resist U.S. pressure, or limit commercial links to avoid sanctions that could disrupt China’s own banks, shipping companies and energy supply chains.
Sources
- Trump says Iran not ready to make the ’right deal
- Treasury Sanctions Crypto Exchanges Funding Iran’s IRGC and Enabling Illicit Finance
- Iran Sanctions
- Foreign Ministry Spokesperson Guo Jiakun’s Regular Press Conference on July 1, 2026
- Iran security chief threatens neighbors against economic measures, and other Mideast developments