US warns of secondary sanctions against countries that continue trading with Iran

Iran rejected the threat outright, with officials in Tehran describing the US posture as economic warfare. Iranian state media quoted authorities as saying the country would not bow to external pressure and would continue to pursue its own commercial relationships, particularly with non-Western partners. The Central Bank of Iran has been at the centre of international sanctions enforcement in recent years.

The dispute comes amid heightened tensions in the Gulf region. Hours before Bessent's remarks, Yemen's Iran-backed Houthis claimed responsibility for a missile attack on a Saudi national shipping company Bahri tanker in the Red Sea. Bahri confirmed that one of its vessels was involved in a security incident shortly after the claim was made. The episode underscored the broader regional stakes of the US-Iran standoff.

Houthi attack on Saudi tanker

President Donald Trump has consistently framed Iran as a central foreign-policy concern, and the sanctions push fits within that approach. Bessent's comments suggested the administration is preparing measures aimed not only at Iran but at third countries whose companies continue to do business with Tehran. Secondary sanctions typically target foreign firms and banks that facilitate transactions with a sanctioned state.

China has been one of Iran's most significant economic partners, particularly in the energy sector, and Beijing's response will be closely watched. Iranian officials have in recent months sought to deepen ties with non-Western buyers as a hedge against Western pressure. The Strait of Hormuz, through which a substantial share of seaborne oil passes, has figured prominently in discussions about potential Iranian leverage.

China and the Strait of Hormuz

Separately, the US officially lifted its designation of Syria as a state sponsor of terrorism. The move was confirmed on the same Monday and was welcomed by Syrian transitional authorities. It marks a notable shift in US policy toward Damascus, though its timing alongside the Iran warning was not officially framed as linked.

Syria delisted as state sponsor of terrorism

Analysts said the combination of steps reflects an administration seeking to recalibrate its Middle East posture across multiple fronts. The sanctions warning is aimed at Iran's revenue streams, while the Syria delisting is intended to open a diplomatic track with a country that had long been isolated under the former Assad government. Both moves were announced on the same day, an unusual pairing that drew immediate attention in regional capitals.

Reactions from European governments were muted in the immediate hours after the announcement, though diplomats said consultations were under way. Several governments have been working to keep channels of communication open with Tehran while complying with existing sanctions regimes. The prospect of new US enforcement risks complicating those balancing efforts.

Iran's central bank has been a focal point of past US sanctions, and any expansion of secondary measures is likely to target financial intermediaries in third countries. Bessent's choice of language suggested the administration wants allies and trading partners to anticipate significant disruption to commercial ties with Tehran rather than incremental restrictions.

The developments add to a volatile security picture in the wider region. The Bahri tanker incident and the Houthi claim highlighted the continuing threat to Red Sea shipping, a corridor that handles a significant share of global trade. Iran has denied arming or directing the Houthis, though the group has previously identified itself as part of Iran's so-called "axis of resistance."