China Warns US Not to Interfere in Iran Cooperation Amid New Sanctions

Beijing has firmly pushed back against Washington's latest threats of secondary sanctions on countries doing business with Iran, stating that its cooperation with Tehran "should not be interfered with or disrupted."

At a regular news briefing on Tuesday, Chinese foreign ministry spokesperson Lin Jian said China "firmly opposes illegal unilateral sanctions" and will take all necessary measures to safeguard its rights and interests. He called on the United States and Iran to agree to a ceasefire and asserted that sanctions will not resolve the underlying conflict.

The statement comes after US Treasury Secretary Scott Bessent unveiled an "economic D-Day" campaign aimed at isolating Iran from the global economy by severing its access to the US dollar system. The plan, described by US officials as "economic asphyxiation," involves sweeping secondary sanctions against nations and entities that continue trade with Tehran. While the US has not officially named specific countries, those considered most vulnerable to retaliation include China, the United Arab Emirates, Turkey, Iraq, the European Union, India, Pakistan, and Russia.

China is Iran's largest trading partner, accounting for nearly one-third of Iran's non-oil foreign trade and about 90 per cent of its oil exports, according to US government data. Beijing reported bilateral trade of $9.96 billion with Iran in 2025. That figure, however, excludes an estimated $31.2 billion in unreported Iranian crude oil exports to China during the same year, according to the US-China Economic and Security Review Commission.

Independent analysis by Kpler indicates that Chinese refiners purchased an average of 1.38 million barrels per day of Iranian oil in 2025. The data shows that independent Chinese refiners often acquire the crude in bulk, rebranding it as Malaysian or Indonesian oil and settling payments through intermediaries outside the dollar-based financial system.

The US Treasury in April imposed sanctions on a Chinese independent refinery for buying billions of dollars' worth of Iranian oil. It also warned Chinese banks that they could face secondary sanctions if they facilitated the trade of Iranian crude.

Lin Jian's remarks underline China's determination to continue economic engagement with Iran, despite mounting pressure from Washington. Beijing has consistently argued that unilateral sanctions lack legal basis under international law and undermine the multilateral order.

The development also spotlights a broader geopolitical divide, with the US seeking to enforce economic pressure while China emphasises its sovereign right to conduct foreign trade. The situation is being closely monitored by global markets and trade partners, as any escalation could have significant implications for energy supplies and international commerce.

China has not yet announced any specific retaliatory measures, but its strong wording suggests it will resist US efforts to curb its trade with Iran. Analysts note that China's continued purchases of Iranian oil have been a key factor in mitigating the impact of US sanctions on Tehran's economy.

The announcement of the new campaign follows years of escalating tensions between Washington and Tehran. The US has reimposed a range of sanctions since withdrawing from the 2015 nuclear deal in 2018, aiming to pressure Iran into renegotiating its nuclear programme. The Trump administration's latest strategy, however, extends beyond direct sanctions to target third-party enablers and financial channels.

Although the US has not officially named countries, it has threatened penalties against "enablers" that continue doing business with Tehran. This includes sectors such as digital assets, technology, gold, aviation, and shipping, according to Bessent. The aim is to cut off Iran's access to the global financial system and starve its economy of revenue.

For its part, China has repeatedly called for dialogue and has maintained that normal trade relations should not be politicised. At Tuesday's briefing, Lin Jian reiterated that China's engagement with Iran is based on mutual benefit and international law.

Experts say the US strategy faces significant challenges, particularly in Asia where many countries rely on Iranian crude. China, India, and Turkey have historically been major buyers of Iranian oil. The effectiveness of secondary sanctions depends largely on whether financial institutions and governments choose to comply.

The US Treasury has already demonstrated its willingness to act. In April, it sanctioned a Chinese independent refinery and issued warnings to Chinese banks, signalling that US enforcement is not merely rhetorical.

But Beijing appears undeterred. Chinese officials have previously argued that the US dollar's dominance should not be weaponised for unilateral foreign policy goals. There have also been discussions among some countries about diversifying away from dollar-based trade mechanisms, though such moves remain limited.

The standoff between the US and China over Iran adds another layer to already tense bilateral relations. Trade disputes, technology competition, and differing views on global governance continue to strain ties between the two largest economies.

As the situation unfolds, the international community will be watching to see whether Washington's economic pressure will succeed in isolating Iran, or whether countries like China can maintain their economic ties in defiance of US sanctions.