President Vladimir Putin and the Emir of Qatar on Monday discussed the Syrian crisis, as global powers seek to push the warring sides towards the negotiating table.

"Russia plays a main role when it comes to stability in the world," Sheikh Tamim bin Hamad al-Thani said at the start of the meeting at the Kremlin.

President Vladimir Putin acknowledged Monday in an interview with German daily Bild that Western economic sanctions over the Ukraine crisis are affecting Russia.

"Concerning our possibilities on the international financial markets, the sanctions are severely harming Russia," he said in a long interview, calling the EU sanctions "a theater of the absurd."

Russia is not trying to bring back the USSR, President Vladimir Putin said in a documentary aired Sunday, but the problem is that "nobody wants to believe it".

Since the beginning of the Ukraine crisis, which saw pro-Russian leader Viktor Yanukovych ousted by pro-European demonstrators, Moscow has accused the West of using "the politics of containment" in a Cold War throwback.

Recep Tayyip Erdogan and Vladimir Putin, leaders with remarkable similarities who built a new era of cooperation between Turkey and Russia, have suffered a ferocious falling-out that will harm relations for years to come.

The two presidents, who forged a strong friendship in over a decade in power, have traded a slew of insults since Turkey shot down a Russian warplane on November 24 on the Syrian border for alleged repeated violations of its airspace.

Russian President Vladimir Putin on Thursday vowed Turkey's leadership would be made to regret the downing of one of Russia's warplanes as Moscow announced a halt to talks on a major gas pipeline project.

As Putin fired another salvo in his mounting war of words with NATO member Turkey his Turkish counterpart Recep Tayyip Erdogan declared he had "proof" that Russia was involved in illegal oil trading with the Islamic State (IS) group in Syria.

Russian President Vladimir Putin on Wednesday made a surprise visit to Crimea, inaugurating an undersea cable project to bring a new power supply to the strategic Black Sea peninsula.

Until late November, Crimea's electricity had mostly been supplied by Ukraine. But the territory's population of nearly two million has been plagued by power cuts since Crimea's four main pylons in Ukraine were blown up late last month.

U.S. President Barack Obama pushed Monday for a "de-escalation" of a furious war of words over Turkey's downing of a Russian warplane, a White House official said.

Obama called for an easing of inflamed Russia-Turkey tensions in a closed-door meeting with Russia's Vladimir Putin on the sidelines of a climate summit in Paris, the official said.

French President Francois Hollande and Russian leader Vladimir Putin agreed Thursday to coordinate strikes against Islamic State, but differences over Syria's future hampered efforts to bring Russia into a wider alliance to fight the jihadists.

Putin indicated France and Russia would swap data to help identify IS targets in Syria, as opposed to other groups opposed to the country's leader, Bashar Assad.

President Vladimir Putin said on Thursday that Russia had not received any apology from Turkish leaders over the downing of a warplane, nor any proposals to compensate Moscow.

"We still have not heard any articulate apologies from Turkey's highest political level nor any proposals to compensate for the harm and damage, nor promises to punish criminals responsible for their crimes," Putin said at the Kremlin in televised remarks.

Russian President Vladimir Putin arrived Monday in Tehran for talks with Iran about the devastating conflict in Syria where the two nations are allied in support of the Damascus regime.

On his first trip to Iran in eight years, Putin met supreme leader Ayatollah Ali Khamenei, the country's ultimate authority, who has backed Syrian President Bashar Assad since an uprising broke out in 2011.