Moscow considered the results of the just-concluded Istanbul meeting between experts on the Iranian nuclear program as hopeful, Russian Foreign Ministry said Thursday.

"Althoguh there remains much to be done before agreements could be reached, this is a hopeful signal that the conversation has been transferring into the professional particular plane," Foreign Minister Sergei Lavrov told reporters here.

Iran and the 5+1 group, including Britain, China, France, Russia, the United States and Germany, held a new round of nuclear talks from Tuesday and Wednesday in Turkey, trying to find common ground for full-fledged talks after previous meetings failed to produce any breakthrough.

The expert-level meeting was necessary to "clarify details of the stances the parties exchanged at the previous rounds," Deputy Foreign Minister Sergei Ryabkov said, adding that relevant parties were still exploring models for resolving current and long-existed problems.

Iran has insisted on the peaceful nature of its nuclear program, which Western countries suspected are being used to produce nuclear weapons.