Just minutes earlier Defense Minister Sergei Shoigu announced Russian Federation will transfer the S-300 air defense system to its ally Syria within weeks, among a raft of measures to improve the country's ability to detect and repel Israeli air strikes. Russia laid the blame squarely on Israel, saying that its fighter jets had pushed the Russian plane into the line of Syria's fire.
Russian Federation in April had hinted that it would supply the S-300 to Assad's government despite Israeli objections.
"The situation has changed, and not due to our fault", the statement said.
Israel says its air strikes on Syria are not a threat to Russia's ally Assad, but that it must carry them out to halt arms shipments to Iranian-backed Lebanese group Hezbollah.
The Israeli pilots' actions "either speak of their unprofessionalism or criminal negligence at the very least", Konashenkov said, reiterating the Israeli airforce was fully responsible for the downing of the plane.
According to the ministry of defense, the Russian military aircraft was shot down before landing at the Hmeimim air base. During a Syrian air defenses counterattack, the Russian spy plane was shot down by an S-200 anti-aircraft missile and its 15 crew members were killed.
According to the halturnerradioshow.com, nearly seven Ilyushin Il-76 military transporters of Russian Air Force have arrived at Khmeimim military airbase on 22 September.
However, Kremlin spokesman Dmitry Peskov said Sunday that the Russian decision "is not directed against third nations", and is primarily aimed at protecting Russian aircraft from further friendly fire.
President Vladimir Putin struck a reconciliatory note, blaming the downing on a "chain of tragic, fatal circumstances". The Russian president also informed Assad of the S-300 delivery, it said.
Shoigu said the new system will "significantly increase" the Syrian army's combat capabilities.
Russian Federation ordered its plane back to base.
Syria's skies, where regional and worldwide powers back different parties in the conflict, are increasingly crowded.
Russian Deputy Foreign Minister Mikhail Bogdanov told Russian news agencies that supplying S-300 to Syria is Russia's "own right" and expressed confidence that this would not hurt Russia's ties with Israel.
The Russian Defense Ministry said Israel's warning came less than a minute before the airstrike.
Moscow will bolster Syria's air defence with a S-300 system and jam radars of military planes striking from off the coast of the Mediterranean following the downing of a Russian plane, its military chief said.
Russian Federation launched its campaign in Syria to support President Bashar al-Assad in 2015 and though the involvement turned the tide of war in favour of Syrian regime forces. For its part, Israel is wary of Iran's growing influence in Syria.
Syrian state TV said insurgents shelled a government-controlled crossing east of Idlib on Monday that was reportedly prepared to allow civilians to leave the province.
Hard-line armed groups have rejected the deal, saying it aims to strip the opposition of weapons and is a victory for Assad's government.