Downing a Turkish warplane over Syrian territory would qualify as aggression, Erdogan told CNN in response to a question on what would happen if a Turkish fighter jet were to stray into Syrian territory.
"This kind of an incident which may happen of course will further push us to take measures. … Of course it will be an aggression against our rights of sovereignty and it is a natural right of [Turkey] to protect those rights," Erdogan said.
The Su-24 was involved in Russia's counterterrorism efforts in Syria aimed at assisting Damascus in its fight against ISIL and other extremist groups trying to overthrow Bashar al-Assad.
Erdogan refused to apologize for the incident, which Russian President Vladimir Putin referred to as a "stab in the back" committed by "accomplices of terrorists."
#SYRIA S-400 AA missile system delivered, deployed and put on air defence combat duty at #Hmeymim airbase pic.twitter.com/JXZ3hky5Wm
— Минобороны России (@mod_russia) 26 ноября 2015
In the wake of the Su-24 crash, Russian defense officials decided to send the S-400 system to prevent similar incidents from happening.