An Iranian-flagged oil tanker pursued by the United States amid heightened tensions between Tehran and Washington changed its listed destination early Saturday to Mersin, a port province in Turkey’s south, after Greece declined to help, the Associated Press reported. 

The crew of the Adrian Darya 1, formerly known as the Grace 1, updated its listed destination in its Automatic Identification System (AIS) to Mersin, which is home to an oil terminal, the AP said.

But Mersin may not be the real destination of the tanker, as mariners can input any destination into the AIS, the AP said, adding that a refinery in Baniyas, Syria was the destination of Adrian Darya had been heading before being seized off Gibraltar in early July according to U.S. authorities. 

There was no immediate reaction from Turkey, the AP said. Turkey has been working together with Iran and Russia over Syrian’s civil war, while Ankara is a vocal critic of U.S. sanctions on Iran.

The Adrian Darya was released from detention off Gibraltar after a five-week standoff over whether it was violating EU sanctions by carrying Iranian oil to Syria.

A U.S. State Department official told Reuters on Thursday that the United States would aggressively enforce its sanctions to prevent the private sector from assisting the Iranian ship.

The official, speaking on condition of anonymity, warned that the United States would act against anyone who directly or indirectly helped the tanker, Reuters said.