US Treasury chief calls on allies to tighten Iran sanctions

U.S. Treasury Secretary Janet Yellen told international partners on Thursday that the United States expects coordinated action to intensify pressure on Tehran’s economy. In a speech delivered at a policy forum in Washington, Yellen warned that the next phase of sanctions will target key sectors that sustain Iran’s nuclear and ballistic‑missile programmes, and she urged allies to decide whether they stand "with us or against us".

The Treasury chief outlined a package of measures that would expand existing restrictions on Iran’s oil exports, limit access to the global financial system, and curb the flow of technology used in weapons development. She said the United States is prepared to move quickly, but the effectiveness of the plan hinges on a unified response from European, Asian and Middle‑Eastern partners.

Yellen highlighted that Iran’s economy has shown resilience despite previous rounds of sanctions, citing continued revenue from illicit oil sales and a growing network of front companies. She argued that only a concerted, multilateral approach can dismantle these workarounds and force Tehran back to the negotiating table over its nuclear agenda.

European officials have not yet committed to the full scope of the proposed actions, and some have expressed concerns about the impact on their own energy markets. Nonetheless, Yellen emphasized that the United States will proceed with the strategy regardless of hesitations, framing the decision as a test of alliance solidarity.

The Treasury secretary concluded by urging governments to align their policies swiftly, warning that delay could embolden Iran and undermine regional stability. She called on partners to share intelligence, coordinate enforcement, and adopt a shared vision for a “squeezed” Iranian economy that can no longer fund destabilising activities.