The strikes came with Syria's splintered opposition due to begin Saudi-organised talks in Riyadh on Wednesday for difficult discussions on forming a united front in potential talks with President Bashar al-Assad to end the country's years-long conflict.
Moscow's latest strikes hit "300 targets of different kinds" in the past three days and helped Syrian special forces recover the black box of the Russian warplane downed by Turkey last month, Defence Minister Sergei Shoigu said.
"We used Calibre cruise missiles from the (Kilo-class) Rostov-on-Don submarine from the Mediterranean Sea," Shoigu told President Vladimir Putin during an encounter broadcast on state television.
"As a result of the successful launches by the aviation and submarine fleet, all targets were destroyed," Shoigu said, adding that oil infrastructure, ammunition depots and a mine-making factory had been hit in the strikes.
Russia launched a bombing campaign in Syria on September 30, saying it needed to target Islamic State (IS) jihadists -- but the West has accused Moscow of seeking to prop up Assad's regime and hitting moderate rebels.
Moscow stepped up strikes against IS after the group claimed responsibility for the bombing of a Russian passenger plane over Egypt's Sinai Peninsula in October, killing all 224 people on board.
- Riyadh talks -
Russia is once again flaunting its military might after having previously fired missiles from warships in the Caspian Sea.
The Russian defence ministry said it had upped the intensity of its strikes in Syria since Saturday, dropping 1,920 bombs over the past four days.
Putin said Tuesday that the Calibre missiles launched from the submarine could be equipped with nuclear warheads -- but said he hoped they would "never be needed in the fight against terrorism".
The latest strikes came ahead of talks in Riyadh which mark the first time representatives of some of Syria's various political and armed opposition factions will come together since the outbreak of the country's conflict in March 2011.
The goal is to form a unified bloc for talks with Assad that world powers hope can be held before January 1.
Washington voiced hope ahead of the Saudi-organised talks, with State Department spokesman John Kirby telling reporters the conference "can be an important step in creating momentum for negotiations, again, under UN auspices, of a political transition".
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But divisions have already emerged over the reported participation of some groups, while armed entities described as "terrorist" organisations, such as Al-Qaeda's Syrian affiliate Al-Nusra Front and the Islamic State group, were not invited.
Previous attempts by regional and other international powers have failed to unite the diverse opposition groups, whose differences have long reflected the struggle for influence among the countries supporting them.
But there has been a growing diplomatic push for a resolution to the conflict, which has killed more than 250,000 people and forced millions from their homes.
- 'Treacherous stab' -
Shoigu, meanwhile, also said Russia had "actively worked" on the region where Turkey shot down a Russian war jet on the Syrian border on November 24, allowing Syrian special forces to recover the plane's black box.
Putin ordered that the black box be analysed "together with foreign experts".
Moscow and Ankara are locked in a bitter feud over the November 24 downing of the jet on Turkey's border with Syria, sparking fury and economic sanctions from the Kremlin.
Putin said an analysis of the black box would help determine the plane's flight path and position, which Ankara and Moscow have furiously disagreed over.
But he warned that no black box findings could assuage Moscow's anger over the incident, which left one of its pilots dead. Another Russian serviceman was killed in the rescue operation.
At informal UN Security Council talks Tuesday Russia denounced the deployment of Turkish troops in Iraq, but the Council did not take a stand on the dispute.
Russia had called the informal talks, which were presided over by the United States, which heads the rotating presidency of the 15-nation council in December and leads the international coalition fighting the Islamic State Group in Iraq and Syria.
"It was very important to call the attention of the Security Council to this situation," Russia's UN envoy Vitaly Churkin.
A "disappointed" Churkin deplored the fact that the United States and other Western members of the Council have refused to call ally Turkey to order or reaffirm Iraq's sovereignty.
He called the Turkish moves "a reflection of the lack of legality in the actions of the international coalition led by the US."
Iraqi ambassador Mohamed Ali Alhakim stressed that Baghdad and Ankara "are working on this bilaterally" and that the talks were "going very well." He said the initiative was not discussed with Moscow.