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 on suspicion it was shipping 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.