ATHENS: An Iranian tanker that has sparked a diplomatic row pitting Tehran against Washington and London is too big to dock in Greece, the country's junior finance minister said Wednesday.

"This is a very large crude carrier, it is over 130,000 tonnes... It cannot access any Greek dock," junior foreign minister Miltiadis Varvitsiotis told Ant1 TV.

Varvitsiotis said the Greek government had "faced pressure" by US authorities over the vessel but insisted that Athens "has sent a clear message that we would not wish to facilitate the transport of this oil to Syria under any circumstances."

Gibraltar, a British overseas territory, seized the tanker on July 4 on suspicion it was transporting oil to Syria in breach of European Union sanctions, triggering a sharp deterioration in relations between Tehran and London. Iran has repeatedly denied any violations.

Varvitsiotis said Athens was not in contact with Tehran over the tanker, which was originally called Grace 1 but has been renamed the Adrian Darya, and had received no request from Iran.

The website Marine Traffic, which earlier this week gave the ship's reported destination as the Greek port of Kalamata, had placed the supertanker carrying 2.1 million barrels of oil some 100 kilometres (60 miles) northwest of the Algerian port of Oran.

The maritime tracker says the tanker is expected to arrive in Kalamata on Monday, but Varvitsiotis suggested it may not dock in Greek waters at all.

"It has named Kalamata as its port of destination but this doesn't mean anything," adding: "It could drop anchor somewhere" else.

Gibraltar's Supreme Court ordered the tanker released last Thursday, with Iranian officials saying a new crew had arrived to pilot the vessel.