Russia on Wednesday accused Iran of indulging in "political demagoguery" after an unprecedented attack from President Mahmoud Ahmadinejad stretched Moscow's already strained patience with Tehran.

Tehran has traditionally counted on Russia to moderate the stance of Western world powers in the standoff over its nuclear programme but Moscow has over the last weeks been increasingly open about its frustration with Tehran.

Ahmadinejad on Wednesday bluntly accused Russian President Dmitry Medvedev of siding with Tehran's enemies, like arch-foe the United States, in the crisis over the Iranian nuclear drive.

His comments were an extraordinary broadside against Russia, usually seen as having the closest political ties to Tehran of any major world power and a key military and technical partner of the Islamic Republic.

"Any unpredictability, political extremism, lack of transparency or inconsistency in decision-making... is unacceptable for Russia", the Kremlin's top foreign policy advisor Sergei Prikhodko said in response.

"No one has ever managed to retain their authority through political demagoguery," Prikhodko added in a statement released by state news agencies.

Despite its strong energy and defence ties with Iran, Russia has backed a new sanctions drive at the UN Security Council which has issued repeated ultimatums for Iran to freeze uranium enrichment.

Moscow has also reacted coolly to a nuclear fuel deal aimed at defusing the standoff that was brokered by Brazil and Turkey earlier this month, a stance which has clearly disappointed Tehran.

Medvedev cautiously welcomed the deal but also expressed concern it may fail to allay the main fear of the international community about Tehran's uranium enrichment operations.

"We hope Russian officials will pay attention, make amends and not let Iranians put them in the line of their historic enemies," Ahmadinejad said in a speech Wednesday.

Iran appears particularly annoyed that Russia and China have joined in with the three other permanent members of the UN Security Council -- Britain, France and the United States -- in discussing a new sanctions text against Tehran.

But Prikhodko rubbished the suggestion by Ahmadinejad that Russia was adopting a pro-American stance in the nuclear crisis.

"Our position is Russian, it reflects the interests of all the peoples of Russia and thus it is neither pro-American nor pro-Iranian."

Russia is building Iran's first nuclear power plant in the southern city of Bushehr, a facility expected to finally come online in August after a series of delays.

It also has a contract to sell sophisticated S-300 air defence missiles to Tehran but has not delivered the weapons amid concerns from Israel and the United States that they could severely impede an air attack.

Western diplomats have suggested that under the text of the resolution against Iran being discussed at the UN Security Council Russia would be unable to deliver the S-300 missiles to Tehran.

Russian lawmakers have disputed this view but this week Tehran's envoy to Moscow sternly warned Russia its credibility would be undermined if it dropped the deal.

"Refusal to deliver the S-300s will strike a blow to Russia's reputation as a reliable arms supplier," Ambassador Mahmoud Reza Sadjadi said.

"It would compel us to question Russia's reliability at such sensitive moments."

He also expressed hope that Russia would be able to dissuade other world powers from imposing sanctions against Tehran.

earlier related report
Iran's Ahmadinejad lambasts Russia over nuclear stance
Tehran (AFP) May 26, 2010 - Iranian President Mahmoud Ahmadinejad launched a stinging attack on Russia Wednesday over its stance on Tehran's atomic drive, accusing it of "siding with those who have been our enemy for 30 years."

Ahmadinejad's comments in a televised speech, during which he also urged both Russia and the United States to back a controversial nuclear fuel deal, drew a swift rebuke from Moscow, which angrily denounced his "political demagoguery."

"The Tehran declaration (on a fuel swap) is the best opportunity. We took an important step and said something very important. There are no excuses left," Ahmadinejad said in the speech addressed to US and Russian leaders.

Moscow, like Washington, has reacted coolly to the nuclear fuel deal aimed at defusing the standoff that was brokered by Brazil and Turkey earlier this month, a stance that has clearly disappointed Tehran.

Russian President Dmitry Medvedev cautiously welcomed the deal but also expressed concern that it might fail to allay the main fear of the international community about Tehran's uranium enrichment operations.

And despite strong energy and defence ties with Iran, Russia has backed a new sanctions drive at the UN Security Council, which has issued repeated ultimatums for Iran to freeze enrichment.

Delivering an extraordinary broadside against a country that has traditionally been seen as enjoying the closest political ties to Tehran of any major world power, Ahmadinejad singled out Medvedev for censure.

"Today it has become very difficult to explain Mr Medvedev's behaviour to our people. Iranians do not understand whether they are our neighbour and friend standing by our side or are after other things," he said in the speech delivered in the southeastern city of Kerman.

"We hope Russian officials will pay attention, make amends and not let Iranians put them in the line of their historic enemies," Ahmadinejad said.

"If I were in the Russian President's shoes I would be more cautious in commenting and decision making about issues pertaining to the great and strong nation of Iran."

His attack left Moscow bristling.

"Any unpredictability, political extremism, lack of transparency or inconsistency in decision-making ... is unacceptable for Russia", top Kremlin foreign policy advisor Sergei Prikhodko said in a statement released by state news agencies.

"No one has ever managed to retain their authority through political demagoguery," Prikhodko added.

He rubbished the suggestion by Ahmadinejad that Russia was adopting a pro-American stance in the nuclear crisis.

"Our position is Russian, it reflects the interests of all the peoples of Russia and thus it is neither pro-American nor pro-Iranian."

Russian news agencies said Prikhodko's remarks were a comment on Ahmadinejad's speech, in which the Iranian president also said the nuclear fuel deal provided an "historic opportunity" to his American counterpart.

President Barack Obama "should bear in mind that if he does not use this opportunity, Iranians are unlikely to give him a new chance," Ahmadinejad said.

"There are people in the world and in America who insist on pitting Mr Obama against Iranians and push him to the point of no return and force him to do something which will forever block the path of friendship with Iranians," he said.

Iran and the United States have not had diplomatic relations for three decades.

On Monday, Iran formally notified the International Atomic Energy Agency of its agreement to the nuclear fuel swap deal, under which it would ship some low-enriched uranium to Turkey in return for higher grade fuel for a Tehran research reactor.

Western governments have been dismissive of the deal, arguing that the international community needs to keep up the pressure on Tehran to heed UN Security Council demands over its nuclear programme.

Brazilian officials said on Wednesday that President Luiz Inacio Lula da Silva had written a letter to Obama and the leaders of France, Russia and Mexico stressing the importance of the nuclear fuel swap agreement and saying it indicated Iran's readiness for dialogue.

Iran is already under three sets of UN sanctions over its refusal to suspend the sensitive process, which lies at the centre of Western fears that the programme is cover for a drive for a nuclear weapon. Iran denies any such ambition.