MOSCOW- Russian President Vladimir Putin signed a decree imposing economic sanctions against Turkey on Saturday, four days after Turkey shot down a Russian warplane near the Syrian-Turkish border.The Kremlin website said the measures would affect imports of some Turkish products, operations of Turkish companies in Russia, and employment of Turkish staff by Russian firms.The Kremlin added that President Vladimir Putin is fully mobilized to tackle what Moscow regards as an unprecedented threat from Turkey following the shooting down of one of its warplanes by a Turkish F-16, the Russian leader's spokesman said on earlier Saturday.In response to the announcement, a senior Turkish official told Reuters that sanctions imposed by Moscow on Turkey only serve to deepen the problem between them."Sanctions like this would only damage relations. These steps do not make anything easier, but deepen the problem," the official said. In comments which underscore how angry the Kremlin still is over the incident, Dmitry Peskov, Putin's spokesman, called the behavior of the Turkish air force "absolute madness" and said Ankara's subsequent handling of the crisis had reminded him of the "theater of the absurd.""Nobody has the right to traitorously shoot down a Russian plane from behind," Peskov told Russia's "News on Saturday" TV program, calling Turkish evidence purporting to show the Russian SU-24 jet had violated Turkish air space "cartoons".Peskov said the crisis had prompted Putin, whose ministers are preparing retaliatory economic measures against Turkey, to "mobilize" in the way an army does in tense times."The president is mobilized, fully mobilized, mobilized to the extent that circumstances demand," said Peskov."The circumstances are unprecedented. The gauntlet thrown down to Russia is unprecedented. So naturally the reaction is in line with this threat."Peskov said Putin was aware of a Turkish request for him to meet President Tayyip Erdogan on the sidelines of the Paris climate change conference next week but gave no indication of whether such a meeting would take place.Erdogan on Saturday said the Paris summit could be a chance to repair Ankara's relations with Russia.Peskov denied Turkish press reports which said Moscow and Ankara had struck a deal for their warplanes to stop flying along the Syrian-Turkish border, saying military ties between the two countries had been severed and a hot line meant to avoid misunderstandings among their pilots dismantled.Peskov, according to the TASS news agency, also spoke of how Erdogan's son had a "certain interest" in the oil industry. Putin has said oil from Syrian territory controlled by Islamic State militants is finding its way to Turkey.Erdogan has spoken of slander and asked anyone making such accusations to back up their words with evidence.Peskov said he "noted" that Turkey's newly-appointed energy minister, Berat Albayrak, was Erdogan's son-in-law.Peskov said there could be up to 200,000 Turkish citizens on Russian soil."What's important is that everyone who is able to use their influence to guarantee at least some predictability in the pattern of Turkey's behavior," said Peskov. "Russian planes should never be shot down."