The Trump administration imposed sanctions on Golden Global Yatirim Bankasi Anonim Sirketi, a Turkish bank it called a "critical financial lifeline" for Iran.

The action is part of "Operation Economic Outcast," a new U.S. effort to isolate Iran from its trading partners.

Treasury Secretary Scott Bessent launched the operation last week.

The Treasury Department said the Istanbul-based bank was set up to help Iran move oil revenues from China to Turkey.

There, the money could be converted into cash and gold.

The bank also knowingly offered services to Iranian financial entities, including some sanctioned by the U.S. in 2022.

Bessent said financial institutions tied to Iran "will continue to find out the hard way that we are serious."

He added that further sanctions depend on whether the international community stops supporting the "murderous Iranian regime."

However, the broader campaign to force Iran's trading partners to cut ties has so far had little effect.

The U.S. has avoided penalizing major partners like China and India, instead issuing warnings and negotiating.

The sanctions came one day after Turkey's state-run Halkbank settled a nine-year U.S. case over Iran sanctions violations.

In that case, officials allegedly moved about $20 billion in Iranian oil revenues.

The U.S. also resumed military strikes on Iran recently, but the outcome of this two-pronged strategy remains unclear.