The S-400 missile system is in a constantly active mode in order to save resources, says the head of the Turkish Defense Ministry. "There is no need to deploy the system when there are no threats," he says.
The system is needed to prevent damage to the country's national interests, he adds. The cost of the system is estimated to be around $1.5 billion, according to the Russian Foreign Ministry. The Russian government has not yet decided on a price for the system, which is currently in use.