US Treasury is expected to announce it will broaden the scope of secondary sanctions on nations/entities doing business with Iran, according to Reuters sources. Any activity within some Iranian sectors will reportedly be subject to secondary sanctions.

Expansions of US secondary sanctions on Iran have historically followed a familiar sequence: a scoped announcement, a designation list from OFAC, and a wind-down period before enforcement bites, with the real constraint arriving only when third-country banks, refiners and shippers reprice their exposure. The transmission channel for crude is less the legal text than the behavioural response of intermediaries: freight, insurance and trade finance for Iranian barrels have tended to tighten well ahead of formal enforcement, compressing the discounts at which sanctioned grades clear into Asian buying and, in past tightening cycles, reducing effective export volumes even where headline flows initially held up. The phrase "some Iranian sectors" matters: whether the scope covers energy specifically or finance, metals and logistics determines whether this is an oil supply story or a broader financial isolation story, and prior episodes have shown the distinction drives very different reactions in the crude curve versus regional FX and shipping rates. Worth noting that "expected to announce" sourced reporting has on previous occasions preceded softer or delayed implementation, so the follow-ons are the official notice, the designated entities, any wind-down carve-outs, and the reaction of the refiners and banks that historically self-sanction early. Enforcement credibility, waivers and the response of the largest buyers of Iranian crude have been the tells in comparable episodes.