Iran said on Tuesday it has managed to overhaul one of the three Russian-made submarines it has in its fleet, despite Moscow rejecting requests for plans and parts.

"At first it was a very difficult task. But with perseverance and determination, our navy proved that it was a doable task," the commander of the Iranian navy, Admiral Habibollah Sayari, was quoted as saying by the state television website.

Russia is ready to help Iran build a new nuclear power plant alongside the first one Moscow helped construct in the city of Bushehr, a top official at the state nuclear firm Rosatom said on Tuesday.

"If it is not forbidden and if it is advantageous, if there is indeed a project -- then yes, we are ready," news agencies quoted Rosatom's deputy head Nikolai Spassky as saying while on a visit to Kazakhstan.

Russia said on Monday it did not support the Syrian government of President Bashar Assad but urged world powers to work for the peace plan of U.N. envoy Kofi Annan and not regime change.

"We do not support the Syrian government. We support the plan of Kofi Annan," Foreign Minister Sergei Lavrov said at a joint news conference with his British counterpart William Hague.

China on Monday condemned a massacre of more than 100 people in the central Syrian town of Houla and called for an immediate investigation to identify those responsible.

Beijing's comments came as U.N.-Arab envoy Kofi Annan headed to Damascus in a bid to salvage his battered peace plan a day after the United Nations condemned the Syrian regime's use of artillery in Houla.

The administration of President Barack Obama is considering working with Russia on a plan calling for the departure of Syrian President Bashar Assad under a proposal modeled on the transition in Yemen, The New York Times reported Sunday.

The newspaper said the plan calls for a negotiated political settlement that would satisfy Syrian opposition groups but that could leave remnants of Assad's government in place.

A Russian consul-general in Japan died after falling down a 30-meter (98-foot) cliff during a ball game at a campsite in the northwest of the country, police said Sunday.

Vladimir Pushkov, 55, who was stationed at a consulate general in Niigata prefecture, was on a camping trip with 13 colleagues and their families, an official at Agano police station in Niigata told Agence France Presse.

Russia's ruling party United Russia confirmed Saturday Prime Minister Dmitry Medvedev as its new chief in a bid to reverse flagging popularity that stoked opposition protests against the Kremlin.

A party congress in Moscow overwhelmingly approved by a show of hands Medvedev's candidacy to take over from President Vladimir Putin as party leader, with no apparent opposition and no other candidate contesting the post.

Four Russian bikers who were arrested in Iraq last weekend and complained of beatings by security forces have been freed and are in Russian custody, a top official said Friday.

"The bikers arrested in Iraq are already in the Russian embassy," Deputy Prime Minister Dmitry Rogozin wrote on his Twitter blog. "Their bikes have not yet been returned. Thank you everyone who helped out."

Russia on Friday called the latest round of talks on the Iranian nuclear standoff "constructive" despite big differences that remain as the parties head for more negotiations in Moscow next month.

"The round was held in a constructive and business-like atmosphere despite the significant differences in approaches that remain," the Russian foreign ministry said in a statement.

Russian intelligence thinks the Superjet liner that crashed during an exhibition in Indonesia may have been sabotaged by the United States, one of the country's most widely read dailies said on Thursday.

In an article titled "Are the Americans implicated in the Superjet crash?" the Komsomolskaya Pravda tabloid cited unnamed officials as saying that Russia's aviation rivals were interested in seeing the plane fail.