US Treasury Secretary Scott Bessent has warned countries that continue buying Iranian oil, trading with Tehran or moving money on its behalf that they now risk economic isolation themselves, as Washington prepares what he called the largest financial offensive ever launched against an adversary.
Bessent laid out the plan in an opinion piece published in the Financial Times under the headline "An economic D-Day is coming for Iran." He is due to announce the specific measures at a press conference on Monday evening.
Invoking the Allied landings in Normandy during the Second World War, Bessent wrote that an economic D-Day was beginning at dawn, describing it as the largest financial offensive ever mounted against an adversary. He argued that with military strikes having already curtailed Iran's capabilities and weakened its nuclear program, the confrontation was now entering its final phase.
Warning to Iran's trading partners
Much of Bessent's warning was aimed not at Tehran itself but at the countries that keep its economy afloat. He said these nations buy and transport Iranian oil, run exchange offices and free trade zones that move money for the regime, allow Iranian flights, maintain ship registries on Tehran's behalf, and look the other way on fuel transfers at sea and misuse of banking systems.
He said that tolerance was now over. Bessent argued that governments treating appeasement of Iran as the safer path needed to reconsider, since they now risked facing isolation of their own. He invoked Pascal's wager to frame the choice facing Tehran's trading partners: keep supporting Iran economically and risk their relationship with Washington, or cut ties with the regime.
Bessent said countries that severed economic ties with Iran would gain stronger access to international capital markets and greater credibility for their economies. By contrast, he said, every country acting as a financial artery for a collapsing regime should expect to share in its isolation. He added that any country that became a haven for terrorism would be branded a "pariah" by the United States.
The Treasury Secretary said the Trump administration was ready to deploy every agency, authority and measure at its disposal, warning that continued ties to Tehran, whether through deliberate cooperation or governments simply overlooking activity, could speed up the economic exclusion of both countries and companies. He also left open the possibility of a renewed military response if Iran attacked US forces or Gulf states, saying President Donald Trump would act swiftly and decisively in that case.
Which countries could be hit
Iran has said it is prepared to withstand economic pressure, pointing to its wide network of allies and trading partners. Several countries stand out as likely targets of the new measures.
China is the largest buyer of Iranian oil, taking more than 80% of Iran's oil exports. The data firm Kpler estimated Beijing purchased an average of 1.38 million barrels a day in 2025. Washington has already sanctioned an independent Chinese refinery over Iranian oil purchases and warned Chinese banks they could face secondary sanctions.
Turkey imports Iranian natural gas and exports industrial goods to Iran, with bilateral trade estimated at around $5 billion to $6 billion a year; Iran accounts for roughly 13% of Turkey's total gas imports. Iraq's trade with Iran exceeded $10 billion in 2025, and Baghdad pays Tehran $4 billion to $5 billion a year for gas used in electricity generation, leaving it exposed to new sanctions.
Oman, which has maintained friendly relations with Tehran for decades and often mediates between Iran and other governments including the United States, recorded $1.5 billion in bilateral trade with Iran in 2025 and $345 million in the first four months of 2026. Pakistan and Iran trade oil, wheat, rice, livestock and pharmaceuticals through formal and informal channels; unofficial trade has pushed the total to around $4 billion, with the two countries aiming for a $10 billion target.
India's trade with Iran has shrunk sharply because of existing US sanctions, falling from a peak of about $17 billion to $4.8 billion in the 2019-2020 fiscal year and just $1.63 billion in 2025-2026, of which roughly $1.3 billion was Indian exports of cereals, tea, coffee and spices. Armenia's trade with Iran reached $768 million in 2025, with about 20% of Armenian foreign trade passing through Iran under a gas-for-electricity swap arrangement. Azerbaijan's bilateral trade with Iran rose 4.5% in the first half of 2026 to $312.6 million, with Azerbaijani imports from Iran at $297 million and exports to Tehran more than doubling to $15.6 million.
What comes next
Bessent said the goal was to cut every economic lifeline sustaining what he called the tyrannical regime, until Tehran stood alone. He closed his op-ed by asking those still doing business with Iran whether they were prepared to bet their future against the resolve of the United States.
Bessent is scheduled to detail the specific measures at a press conference on Monday evening.
