Russian Foreign Minister Sergei Lavrov said Saturday that Iran nuclear talks had eliminated the fundamental areas of disagreement and there was a real chance of reaching a deal next week.

"Our general impression is that there is a very good chance that must not be missed," the foreign ministry cited Lavrov as saying in a transcript of the interview broadcast on TVTs television.

He said he was referring to a discussion with the European Union policy chief Catherine Ashton on the sidelines of the ASEM conference of European and Asian foreign ministers last week.

"Now there are no fundamental disagreements on the practical questions that need to be resolved," Lavrov said, with both Iran and the group of six world powers ready to "seek points of contact."

What is needed now is to "correctly draw up the agreement we have reached in diplomatic language, so that it is truly a joint document," he said.

Yet he warned against adding further conditions for Iran to comply with when talks on curbing its nuclear programme resume in Geneva on Wednesday.

Lavrov said the talks should not focus on "submitting some artificial additions that do not help solve the main task and don't essentially change anything."

"The steps that need to be taken to defuse the situation and create conditions to finally regulate the Iranian nuclear problem are clear both to the group of six and to Iran," he said.

Some reports said that talks last week ended in deadlock because of reservations expressed by France which were subsequently adopted by other powers.

Lavrov in the interview declined to comment specifically on France's position.

He was talking to television host Alexei Pushkov, who also chairs the foreign affairs committee of the Russian parliament's lower house.

A Russian foreign ministry source said Tuesday that the failure to agree a historic deal at the talks in Geneva that ended on Sunday was "not the fault of the Iranians."

The so-called P5+1 group negotiating with Tehran is made up of the five permanent members of the UN Security Council -- Britain, China, France, Russia and the United States -- plus Germany.

This year's election of new Iranian President Hassan Rouhani, seen as a relative moderate, has given fresh impetus to the negotiations which had faltered in recent years.

Iran denies seeking or ever having sought to build the atomic bomb while steadily expanding its nuclear programme over the years in defiance of multiple UN Security Council resolutions and sanctions.

Iran is a key regional ally of Moscow, while Russia has helped it develop nuclear power generation and completed its first nuclear plant at Bushehr.