"We are confident that the agenda of the meeting must be all-encompassing. Of course, it should include issues to help 'fill in the blanks' over Iran's nuclear program and cooperation with the IAEA will be necessary for that," Lavrov said.

The minister emphasized that possible application of force would just aggravate the problem and only peace talks could hit home.

"No issue can be settled using a heavy-handed method. Even after using force, people have to come to the negotiations table and hold talks."

However, on Wednesday Iranian Acting Foreign Minister Ali Akbar Salehi said Tehran would not discuss its nuclear program in Istanbul.

"We will absolutely not recognize the negotiation if the other side wants to negotiate on the issue of the [Iranian] nuclear dossier," Salehi said.

The West, led by the United States, suspects Iran of pursuing a secret nuclear weapons program, but the Islamic Republic, under a few sets of international sanctions already, insists it needs nuclear power only for civilian purposes.

The Iran Six, which comprises Russia, the United States, China, Britain, France and Germany, has been trying since 2003 to convince Iran to halt its uranium enrichment program and to alleviate concerns about its nuclear ambitions.