TEHRAN (FNA)- Three European countries owe a sum of $4 billion to Iran for unpaid crude supplies from the energy rich nation, an official announced on Saturday.

"Spanish oil companies have settled their accounts with Iran, but the Royal Dutch Shell, Italy and Greece owe a total sum of $4 billion to Iran," the National Iranian Oil Company's International Relations Affairs Director Seyed Mohsen Qamsari told reporters on the sidelines of the 20th International Oil, Gas, Refinery and Petrochemical Exhibition in Tehran on Saturday.

He also added that the giant oil firm, Total, has also paid its debts to Iran.

ON Friday, Iranian Oil Minister Bijan Namdar Zanganeh and CEOs of several German oil companies discussed resumption of the latter's operation and partnership in Iran's oil, gas and petrochemical projects.

Zanganeh and managers of the German oil giants discussed new deals in a meeting in the presence of German Energy Minister Sigmar Gabriel in Berlin on Thursday.

"We will try to prepare the grounds for better cooperation in the days after the sanctions are removed," the Iranian oil minister said before meeting the German oil giants.

Zanganeh arrived in Germany on Wednesday night to attend the international energy conference and hold talks with German oil giants.

"The reason for Zanganeh's presence in the conference is told talks with some renowned German firms which can influence Iran's oil industry in the future," Deputy for international affairs and trading Amirhossein Zamaninia told FNA on Wednesday.

He said that a team of German energy experts recently visited Iran's gas rich regions in South Pars, Southern Iran, and continued, "Zanganeh's visit can also result in the development of Iran's oil industry."

By Fars News Agency