The International Transport Workers' Federation slammed the US Thursday, accusing officials of using seafarers as "patsies" in geopolitical disputes.

The rebuke comes after the US State Department threatened the revoke the visas of crewmembers aboard ships transporting Iranian oil on anti-terrorism grounds 15 August in response to the ongoing controversy around the 300,600-dwt Adrian Darya 1 (built 1997).

"As a global union federation, we recognise that geopolitical issues and official sanctions are beyond our purview," said Dave Heindel, the union's seafarers section chair.