U.S. Pressure on Iran Builds as EU Joins Sanctions Push and South Korea Weighs Military Role

The European Union has formally backed Operation Economic Outcast, the Trump administration’s campaign to cut Iran off from the global financial system. U.S. Treasury Secretary Scott Bessent welcomed the move, saying Washington and its allies intend to eliminate Tehran’s remaining financial lifelines.

The campaign, launched in late August, targets multiple sources of Iranian economic activity. Measures focus on the country’s access to digital assets, advanced technology procurement, gold reserves, commercial aviation and shipping, with Washington seeking to increase the financial cost of supporting Tehran.

The EU said additional economic pressure is intended to counter Iran’s destabilizing activities while supporting a return to peace negotiations. Brussels already maintains separate sanctions targeting Iran’s nuclear and ballistic missile programs as well as its military support for Russia.

Iran strongly criticized the European decision. Its foreign ministry accused the bloc of supporting what Tehran describes as U.S. economic coercion, highlighting the widening diplomatic divide surrounding Washington’s strategy.

The U.S. is also threatening secondary sanctions against countries and financial institutions that continue facilitating Iran-related transactions. Bessent has indicated that Washington could introduce new measures weekly, initially focusing on banks and potentially cutting targeted institutions off from the dollar-based financial system.

That strategy could have major implications for China, which was Iran’s largest trading partner and purchased around 90% of its sanctioned crude exports before the war. Washington’s effort to isolate Tehran financially could therefore increasingly intersect with its broader economic relationship with Beijing.

Pressure is simultaneously building on the military front. South Korea is considering several forms of assistance, potentially including a military role supporting U.S. efforts to reopen the Strait of Hormuz to commercial shipping.

Seoul has stressed that no final decision has been made, despite local reports suggesting troops could be deployed to the Gulf region before the end of the year. Any deployment could also require parliamentary approval.

The discussion comes amid signs of tension between Washington and Seoul over South Korea’s limited military support for the Iran campaign. The U.S. recently scaled back a joint military exercise and canceled another scheduled landing drill as it seeks greater assistance from allies.

Meanwhile, fighting around Iran has intensified. U.S. forces carried out another wave of strikes against Iranian military targets following attacks on American forces and commercial vessels, while Iran retaliated with missile launches against U.S. bases across the Middle East.

The Strait of Hormuz remains at the center of the confrontation. Shipping activity through the strategic passage remains subdued, while vessels using routes near the Omani coast continue to face security risks.

The U.S. has also maintained a naval blockade designed to restrict vessels entering or leaving Iranian ports and disrupt the country’s crude exports. U.S. Central Command said it had redirected 87 commercial vessels, disabled three and boarded two as part of enforcement operations.

With the EU joining Washington’s economic campaign and South Korea considering a more direct role, pressure on Iran is becoming increasingly multinational. The next phase will depend on whether tighter financial isolation and military measures can reopen a critical global energy route without pushing the confrontation into an even broader regional conflict.