US Treasury Secretary Scott Bessent said on April 15 in Washington that the US is working with Persian Gulf allies to obtain data on bank accounts linked to members of the Iranian government and is contacting international lenders, including in China, to choke off Iran-related transactions.

He warned that purchases of Iranian goods are prohibited and could trigger secondary sanctions in the newest crackdown on Iranian-held assets across the Gulf.

The remarks signal a sharper enforcement phase as Washington seeks to tighten compliance with its sanctions regime and close long-standing financial channels used by Tehran. By leveraging Gulf-based financial intelligence and pressuring Asian banks, the US aims to disrupt cross-border settlement networks that have helped sustain Iranian trade despite restrictions.

The American push puts countries like the United Arab Emirates into a bind as they host more than 200,000 Iranians, with many Emirati nationals having Iranian heritage from before the formation of the UAE. 

“We are partnering with our Gulf allies,” Bessent said, adding they are “much more willing” to share account information tied to Iranian officials.

He said the outreach extends to “banks, including Chinese banks”, to remind them that “any Iranian goods purchases are forbidden” and that dollar transactions would be sanctioned. “We will press for secondary sanctions if there’s a problem,” he said.

According to US officials, letters have been sent to banks in jurisdictions including Oman, the United Arab Emirates, Hong Kong and China, citing evidence that Iranian funds linked to illicit activities have been routed through regional and Asian financial hubs.

The warnings mark a first step towards potential secondary sanctions that could cut offending institutions off from the US financial system and a new programme by the American leadership. 

The push comes ahead of the expiry on April 19 of a US waiver linked to Iranian oil sales at sea.

Secondary sanctions, a cornerstone of US policy since 2018, target non-US entities dealing with Iran, effectively forcing global banks and traders to choose between access to the dollar system and business with Tehran.

Iran, for its part, has long sought access to more than $100bn in overseas assets frozen under successive sanctions rounds, making financial channels a central battleground in any prospective negotiations.