U.S. Secretary of State Mike Pompeo has urged the European Union to condemn Iran, saying it lied over where oil from the tanker Adrian Darya 1 would be off-loaded.
"Oil from the #AdrianDarya1 has been offloaded in Syria, proving that Iran lied to the UK and Gibraltar...EU members should condemn this action, uphold the rule of law, and hold Iran accountable," Pompeo wrote on Twitter on October 9.
The Adrian Darya 1 has been at the center of a dispute between Tehran and the West, which has raised concerns that the ship intended to violate sanctions by unloading its suspected 2 million barrels of oil in Syria.
The vessel was detained in July and had reported various destinations since it was released by Gibraltar authorities in mid-August on the promise that its cargo was not bound for Syria.
It had been held for six weeks after being detained by British commandos.
Iran has denied suggestions the oil would end up in Syria, saying only the purchaser of the ship's cargo would decide its ultimate destination.
The ship appeared to eventually turn off its location transponders off the coast of Syria, but U.S. officials said satellite images showed it near the Syrian port city Tartus.
The Tartus naval facility in Syria is used by Russia to help support Moscow and Tehran ally President Bashar al-Assad in his ongoing eight-year war against armed opponents.