Russian defense officials say they delivered the missile system free of charge because it is the country's main contribution to the integrated air defense system.

"We have completed the project on free of charge S-300 air defense system deliveries to Kazakhstan," Russian Defense Minister Sergei Shoigu said during a meeting according to Sputnik International.

Russian state-owned media outlet Tass reports the Commonwealth of Independent States, a loose alliance of former Soviet states including Kazakhstan, has plans to further develop its joint air defense system.

"We have approved for 2016 a plan of work of the Defense Ministers' Council of the CIS countries and a plan of common steps on the joint air defense system," Shoigu added.

The S-300 missile defense system was developed by the Soviet Union and now used by the Russian government and other armed forces around the world as a surface-to-air defense system against airborne threats.