Russia's envoy to the UN nuclear watchdog said on Monday he expected a historic nuclear deal between Iran and world powers to be implemented in January, leading to sanctions against Tehran being lifted.

At talks in Vienna, senior officials from those major powers discussed with Iran a text they have prepared that would close the International Atomic Energy Agency's 12-year investigation of Tehran's past activities while ensuring the IAEA could still check for signs of suspicious behaviour.

Under the deal, Iran must scale back its nuclear programme, including its stockpile of low-enriched uranium - which it plans to do via a swap for non-enriched forms of uranium with Russia, to remove concerns it could be put to developing nuclear bombs.

That swap will be done before the end of the year, the Russian envoy to the IAEA, Vladimir Voronkov, told reporters.

Iran has said it will fulfil all its commitments under the July agreement only if the IAEA's Board of Governors passes a resolution formally closing its investigation into Iran's nuclear past when the board meets on Dec. 15.

The draft resolution of the IAEA Board of Governors drawn up by the major powers -- France, Britain, Germany, the United States, Russia and China -- and sent to other states on Monday contained provisions that both sides could claim as victories.

"(The board) also notes that all the activities in the road-map for the clarification of past and present outstanding issues regarding Iran's nuclear programme were implemented in accordance with the agreed schedule and further notes that this closes the Board's consideration of this item," the text said.

The draft resolution, obtained by Reuters, also said the board would eventually no longer be seized of "Implementation of the NPT Safeguards Agreement and relevant provisions of Security Council resolutions in the Islamic Republic of Iran", referring to the nuclear Non-Proliferation Treaty.

That phrase, and a shorter version before the relevant U.N. Security Council resolutions were passed, has been the title of the IAEA's regular reports on its investigation of Iran's nuclear activities since 2003.

SOMETHING FOR EVERYONE

The draft resolution did, however, also provide for the board to tackle a new item covering "implementation and verification and monitoring" of the July deal in Iran, and for the IAEA to provide quarterly reports on Iran's implementation of its commitments under the accord.

More generally, it requests the head of the agency to "report, in this regard ... to the Board of Governors for appropriate action, and in parallel to the United Nations Security Council, at any time if the Director General has reasonable grounds to believe there is an issue of concern."

Earlier on Monday, Iran's top nuclear negotiator, Abbas Araqchi, who met with senior officials from major powers in Vienna, told Reuters after the meetings he was satisfied with the draft resolution and expected it to be adopted next week.

For sanctions on Iran to be lifted, the IAEA must first verify that the Islamic Republic has honoured all its commitments under the July deal, including dismantling large numbers of its centrifuges for uranium enrichment and filling parts of its Arak nuclear site with cement.

The IAEA report on Iran's nuclear past, which was issued last week, strongly suggested Tehran had a secret nuclear weapons programme before 2003, but, in a sign of the shift in relations since July, Western powers voiced little concern.

Araqchi said Iran rejected the findings of the report about its programme before 2003, but added that, in Iran's view, overall the document showed the peaceful nature of Iran's atomic activities.

"We believe that based on this final assessment the Board of Governors should close the so-called PMD issue," he told reporters, referring to the report into what is also known as the "possible military dimensions" of Iran's nuclear past. – Reuters