Iran will receive the bulk of the S-300 air defense missile systems it ordered from Russia by the end of the year.

Iran will receive the bulk of the S-300 air defense missile systems it ordered from Russia by the end of the year, Tehran's defense minister has said.

"We signed a contract with Russia. It is being done. We will acquire a large portion of the systems by the end of this year," Hussein Dehghan told state television late Tuesday.

He said Iranian troops were being trained in Russia to operate the surface-to-air missile systems.

This week, the state-run Russian Technologies corporation (Rostec) announced the signing of a delivery contract in Tehran for S-300 missiles.

Moscow in April lifted a ban dating from 2010 on selling the missile systems to Iran, ahead of Tehran sealing a final historic deal with world powers in July to curb its nuclear program.

Russia will provide Iran with a "modernized and updated" version of the missile systems, following up on an initial contract signed in 2007, Rostec Director General Sergey Chemezov said in a statement.