Russian Defense Minister Sergei Shoigu on Wednesday announced new measures to step up protection of the country's military personnel and aircraft stationed at Hmeimim airbase in Syria.

New-generation S-400 Triumf anti-aircraft missile systems would be deployed in Hmeimim airbase, said Shoigu, who added Russia's Moskva missile cruiser is ready at new combat duty position near Syria's Latakia "to destroy any air target of potential danger to our aircraft."

All Russian operations in Syria would only be carried out under cover of fighter jets, said the Russian defense official, who disclosed military contacts with Turkey would be frozen completely.

Those defense measures were taken on the orders of President Vladimir Putin after Turkey shot down a Russian Su-24 warplane Tuesday over its alleged airspace violation and ignorance of multiple warnings, which Russia vehemently denied.

The rescued pilot of the Su-24, Konstantin Murakhtin, told reporters later in the day that no visual or video warning was received from the Turkish side, ruling out possibility of violating Turkish airspace.

"If they wanted to warn us, they could have shown themselves, taken a parallel course, but there was nothing. And the rocket struck us in the tail suddenly. We didn't even visually observe it to be able to make an anti-missile maneuver," Tass news agency quoted Murakhtin as saying.

Murakhtin assured "there wasn't even a risk of (the Russian warplane) entering Turkey" as the plane was under control of the crew at the time.

Murakhtin was rescued by Russian and Syrian forces after 12-hour mission, while another pilot, the jet commander, was killed by ground fire during landing in Syrian territories.

In addition to the statement given by the survived pilot, Russia presented photos and video clips at an emergency meeting of the Collective Security Treaty Organization (CSTO) Permanent Council, in an attempt to prove no violation of Turkish airspace by the Russian plane.

While accusing Turkey of flagrantly violating international laws for its act, the CSTO referred to the memorandum of understanding signed last month between Russia and the US on safe flight operations over Syria, claiming the MOU "applies to all coalition countries including Turkey."

The stance was reiterated Wednesday evening by Russian Foreign Minister Sergei Lavrov during a telephone conversation with US Secretary of State John Kerry.

"The unprovoked attack by Turkey...is a gross violation of the Russia-US memorandum, which Washington assumed responsibility for compliance with the rules by all parties of the US-led coalition, including Turkey," an online official statement quoted Lavrov as saying.

The two were said to have continued exchanging opinions regarding the prospects of launching political settlement process of the Syrian conflict, as well as other international and regional issues.

While warning of damages to Moscow-Ankara relationship, Russia ruled out negative effects on its anti-terrorist airstrike operations in Syria.

Lavrov earlier in the day said though the incident leads to serious reassessment and revision of relations with Turkey, Russia is not going to war with Turkey.

Demanding more explanations from the Turkish side, Lavrov said Russia is ready to share evidences including objective data released by the Defense Ministry on the jet's route.

Kremlin spokesman Dmitry Peskov regretted Wednesday that no more high-level contacts were made between Moscow and Ankara, except for the phone conversation made earlier between Lavrov and his Turkish counterpart.

Expressing doubts over Turkey's intent on joint anti-terror fight, Peskov said "this obviously doesn't apply to other members of the US-led coalition."

The spokesman also stressed the Syrian-Turkish border areas won't be excluded from Russia's list of terrorist targets for strikes.

Lavrov on Wednesday also noted accumulating factors in Turkey "represent direct terrorist threats to Russian citizens."

On Tuesday, the Foreign Ministry suggested Russians scrap trips to Turkey for tourism or any other purposes, while Russian Federal Tourism Agency recommended travel agents halt promotion or sale of package tours to Turkey.