After Turkish President Recep Tayyip Erdoğan ordered that the Turkish Armed Forces be put on the highest alert, the Turkish General Staff increased the number of fighter jets patrolling the Turkish-Syrian border, reports KavkazCentr citing  CNN Türk.

From now on, 18 F-16 fighter jets of the Turkish Air Force will be patrolling the Turkish-Syrian border. All Turkish ground troops and combat aircrafts have also been put on heightened combat readiness.

It was reported earlier that Kremlin threatened sending S-400 air-defense missile systems to its Khmeymim military base in Syria following the shooting down of a Russian SU-24 fighter jet.

In its turn, Pentagon mentioned considering stationing EA-18 Growler electronic warfare aircrafts at its airbase in Turkey to counter the Russian S-400, Voyennyi Informator reports quoting sources within the US Defense Ministry. Interestingly, the S-400 air-defense missile system is designated by NATO as SA-21 Growler, too.

The Boeing EA-18 Growler is a carrier-based electronic warfare aircraft, a specialized version of the two-seat F/A-18F Super Hornet, which is designed for jamming air-defense systems, including the S-400.

In the meantime, the Russian President continued to engage in threatening rhetoric towards Turkey saying in his Thursday speech that ‘the Turkish government has not offered him any meaningful apologies’ and repeating accusations of ‘a stab in the back’.

“I cannot help saying that we find it absolutely inexplicable that those who we considered partners and allies in the fight against terrorism treacherously stabbed us in the back. I am talking about the shooting down of a Russian fighter jet by the Turkish Air Force,” Putin said.

It was reported earlier that Russians treacherously avenged the shooting down of the plane by destroying a convoy carrying relief aid to Syrian refugees, an act which essentially constituted a war crime.