Iranian media reported that Tehran's ambassador to Greece, Ahmad Naderi, visited on Wednesday the Iranian oil tankers Greece seized under US orders in mid-April. 

Naderi pledged that Iran will make every diplomatic effort to restore its control over the vessel.

Iranian officials had been previously banned by Greece from coming on the deck and meeting the crew.

"We are determined to use all diplomatic and legal capacities to prevent American piracy and to protect the property of Iranian people," Naderi was quoted as saying by the Tasnim news agency. 

Greek authorities had been impounding the ship, which was sailing under the Iranian flag, since April 20, sources told Al Mayadeen in May.

The tanker, which had been sailing under the Russian flag since April 8, changed its flag, sailing under Iran's, and changing its name from Pegas to Lana before entering Greek waters, knowing that the European Union, unlike the US, has not imposed sanctions on Iranian oil.

Greek media outlets reported at the time that the US asked Greek judicial authorities to impound the shipment, which Washington later stole, citing a bilateral legal trade agreement between Washington and Athens. 

Iran later seized two Greek oil tankers on May 27, a mere two days after the news of Greece seizing Iran's tanker was leaked. The Iranian leader later stated on June 4 that the seizure of the tankers was in reprisal for Greece's "theft" of Iranian oil.