"For restoration of [Iran's] oil sells to Greece after the sanctions removal, first, the issue regarding [Athens's] debts must be settled inasmuch as new deals pend on finalization of the previous ones," said Zangeneh following a meeting with Greek Minister for Foreign Affairs Nikos Kotzias in Tehran. 

He said the Greek company Hellenic Petroleum alone owes Iran some 755 million dollars for its oil purchases from Tehran, adding that during his meeting with Kotzias "some proposals were put forwards for settlement of the debts".

He also said cooperation of Iran and Greece in other areas will also depend on the debts' settlement, and expressed hope that it will be soon resolved. 

"The purchase of Greek refineries by Iranian companies is a good thing to happen while the Ministry of Petroleum does not directly buy Greek refineries," he added.  

The delegation includes representatives of Aegean Airlines as well as businesses involved in the area of construction materials and food industry. Representatives of Greek pharmaceutical companies such as ELPEN, Demo and Vianex were also on board the delegation.

In 2011, Greece relied on Iran for more than half of its oil imports during some months after international traders and oil majors halted supplies and banks refused to provide financing for fear that Athens would default on its debt.