Will Iran and UK swap the seized tankers?
Iran's President Hassan Rouhani hinted that if UK releases the Iranian captured tanker, then his country will return a British-flagged vessel it seized last week.
"If Britain steps away from the wrong actions in Gibraltar, they will receive an appropriate response from Iran," Rouhani said on Wednesday during a weekly cabinet meeting.
The Grace-1 supertanker was seized off the British overseas territory on Spain's southern coast on July 4. It was suspected to ship oil to Syria, in breach of EU sanctions. Some two weeks later, Iran seized the British-flagged Stena Impero in the strategically important Strait of Hormuz, claiming that it had collided with a fishing boat and violated international law.