Expert-level nuclear talks between Iran and major world powers to discuss the details of a possible comprehensive deal on Tehran's nuclear program were "constructive, " Tehran Times daily quoted an Iranian nuclear negotiator as saying on Saturday.

The talks were "useful" and the subjects raised by both sides were discussed during the "serious" talks, Hamid Baeidinejad, the head of Iranian expert-level nuclear negotiating team said ahead of a fresh round of high-level nuclear talks in the Austrian capital Vienna on March 18.

He will convey the results of the recent 3-day talks to Iranian foreign ministry officials, Baeidinejad said without providing further details, according to official IRNA news agency.

The expert-level talks, held from March 5 to 7 in Vienna, followed an interim agreement reached between the Islamic republic and the P5+1 group in Geneva on Nov. 24 to hammer out a final agreement on Iran's controversial nuclear program.

Under the deal Iran agreed to freeze part of its nuclear activities in exchange for a relief of the West's sanctions on its economy.