US to announce Iran sanctions Monday; Tehran warns of retaliation against participating nations

The Donald Trump administration has announced it will unveil specific sanctions against Iran on Monday (local time), as Tehran warned it would treat any country joining the US economic campaign against it as an enemy.

Treasury Secretary Scott Bessent is scheduled to hold a press conference at 2 p.m. Eastern time Monday — 3 a.m. Tuesday Korean Standard Time — to announce detailed economic measures against Iran. In a Friday interview with CNBC, Bessent made clear that countries trading with Iran would also face intense pressure, saying it was a choice of "either you're with us or against us." Donald Trump has similarly warned that financial institutions, companies and government bodies providing Iran with an economic lifeline would pay a steep price.

The United States has already imposed sweeping economic sanctions on Iran for decades. Since the Trump administration took office for a second term, the Treasury Department's Office of Foreign Assets Control has sanctioned more than 1,000 Iran-linked individuals, vessels and aircraft, and has added maritime, energy and financial sanctions since the war began.

Washington has also maintained a naval blockade against Iran, which has in effect sealed off the Strait of Hormuz. US Central Command said Sunday it had repositioned 70 vessels to enforce maritime control over Iran. The blockade is part of a strategy to strangle the Iranian economy by cutting off seaborne trade, including oil exports.

With ceasefire negotiations deadlocked, the United States has moved toward an all-out economic war, deploying an unprecedented level of sanctions and pressing the international community to join in. Washington has concluded that international cooperation is essential to forcing a country that has withstood decades of sanctions to yield. Josh Lipsky, senior director of the Atlantic Council, told Bloomberg that squeezing an economy already under sanctions for more than 40 years would be difficult without broader global coordination.

As the prospect of all-out economic war loomed, Iran warned Saturday that it would treat any country joining the US economic sanctions campaign against it as an enemy.

According to AFP, Mohsen Rezaei, secretary-general of Iran's Supreme National Security Council, said on state television: "We declare to all nations: do not join the 'economic war' the United States is waging." He added that "any country that participates in imposing economic sanctions will be considered an enemy."

Mohammad Baqer Qalibaf, speaker of the Iranian parliament and a key figure in ceasefire negotiations between Iran and the United States, posted a cartoon and commentary on X on Sunday predicting that the US "maximum economic pressure" campaign would ultimately boomerang back on Washington.

Countries that refuse to join the sanctions and continue trading with Iran are expected to face consequences including being barred from US financial institutions, account freezes, asset freezes within the United States, and individual sanctions. If Iran designates a specific country as an enemy state, vessels from that country could be denied passage through the Strait of Hormuz — and if the country is a neighbor, a military strike would become one of the scenarios on the table. How Washington ultimately pressures the international community into joining the sanctions campaign is expected to determine the trajectory of the economic confrontation.