WASHINGTON, - The US Treasury Department imposed sanctions on Wednesday on Karnakis & Karnakis, a law firm based in Greece and Panama, saying it had for years provided legal assistance to Iranian shipping networks.

The US Financial Crimes Enforcement Network also issued an administrative subpoena to advance an investigation into a Greek bank over potential ties to Iran, according to a Treasury statement, which did not name the bank.FINCEN also issued requests for information to six other European banks that it did not name over relationships with Iranian financial institutions under US sanctions."

Whether you are conducting illegal oil transfers at sea or sitting in the corner office of a law firm, if you are supporting the Iranian regime, we will find you and sanction you," Treasury Secretary Scott Bessent said in a release.

Washington has held off striking Iran this month in the war that the US and Israel launched on February 28, and instead has continued the blockade of Iranian ports and issued waves of sanctions on Iranian shipping networks and those who the US says aid them.

State Department spokesman Tommy Pigott said Karnakis & Karnakis for years "set up shell companies to hide the true owners of vessels carrying Iranian oil, petrochemicals, and steel."

He said the firm created companies that served as fronts for networks selling millions of barrels of Iranian oil to benefit the Islamic Revolutionary Guard Corps Quds Force and the Houthis. Karnakis & Karnakis did not immediately respond to a request for comment.

Treasury also imposed sanctions on Singapore- and UAE-based shipping agents that it said directly aid Iranian shadow fleet operations.