The United States has warned countries and companies doing business with Iran to cut their ties or risk facing secondary sanctions, as the Donald Trump administration steps up economic pressure on Tehran.
US Treasury Secretary Scott Bessent on Monday described the move as an “economic D-Day” and said Washington was launching an “economic onslaught” against Iran’s financial connections around the world.
However, the Treasury Department stopped short of imposing penalties on countries at the centre of the warning, saying it would give them time to comply.
The department announced sanctions against 60 individuals, entities and vessels, but the list did not include Chinese financial institutions suspected of helping Iran sell its oil.
Bessent said Washington was not seeking to disrupt the global financial system and wanted to give countries a “cure period” before taking further action.
But he warned that the grace period would be short.
“If they facilitate transactions and are part of the ecosystem that turns Iranian oil into money, into repression, they will be targeted,” Bessent said when asked whether Chinese banks could face sanctions.
China has remained the biggest buyer of Iranian oil for several years, making its financial institutions a key focus of Washington’s sanctions campaign.
The timing of any action against Chinese banks could also have wider implications for US-China relations, with Trump and Chinese President Xi Jinping expected to meet in Washington in late September.
Five sectors targeted
The latest US measures broaden the activities that could attract secondary sanctions to five areas of Iran’s economy digital assets, gold, technology, aviation and shipping.
Businesses in China, the United Arab Emirates, Singapore and other countries were among those targeted, including a cooking-oil refinery in France.
Bessent also indicated that the Treasury Department could announce sanctions against a financial institution before the end of the week, although officials did not provide further details.
The announcement comes as the war between the United States and Iran approaches its six-month mark.
Although heavy fighting has eased, diplomatic efforts to end the conflict have stalled, while oil and raw-material shipments through the Strait of Hormuz remain blocked.
The disruption has kept energy prices elevated and increased pressure on economies that depend on oil supplies through the strategic waterway.
Daniel Fried, a former US State Department sanctions coordinator now with the Atlantic Council, said the latest announcement had not matched the expectations created by the administration’s rhetoric.
However, he argued that sustained economic pressure could be preferable to a return to intensified military action.
Decades of sanctions
Washington has imposed sanctions on Iran for decades, targeting the country’s oil revenues, weapons procurement networks and businesses linked to the Islamic Revolutionary Guard Corps.
The sanctions restrict designated entities from accessing the US dollar-based financial system.
Iran, however, has repeatedly sought to evade the measures by creating front companies, registering new vessels and establishing alternative business networks.
The Trump administration has recently expanded sanctions against Chinese “teapot” refineries accused of buying Iranian oil and against the so-called shadow fleet of tankers transporting Iranian crude.
Reuters has reported that the US naval blockade has already discouraged some Chinese buyers from purchasing Iranian oil, potentially reducing the impact of additional sanctions on China.
Bessent also singled out Iran’s Bank Melli, which has branches across Europe, the Middle East and Asia.
“Every branch of Bank Melli must be shuttered and dark,” he said.
The US Treasury says it has imposed Iran-related sanctions on more than 1,000 people, vessels and aircraft since Trump returned to office in 2025.
Recent measures have also targeted Iran’s shadow oil fleet, shipping insurers, weapons procurement networks and digital exchanges, with an estimated $500 billion in Iran-linked cryptocurrency frozen.
The latest warning signals that Washington is preparing to widen the economic pressure beyond Iran itself, putting countries and businesses that continue to maintain commercial links with Tehran on notice.
