ANKARA (Reuters) - Iran has deployed the Russian-supplied S-300 surface-to-air missile defence system around its Fordow underground uranium enrichment facility, Iranian state media reported on Monday.

File photo of the S-300 air defence system launching a missile during the International Army Games 2016 at the Ashuluk military polygon outside Astrakhan, Russia, August 7, 2016. REUTERS/Maxim Shemetov

Iranian state TV on Sunday aired footage of deployment of the recently delivered missile system to the nuclear site in the central Iran.

“Our main priority is to protect Iran’s nuclear facilities under any circumstances,” Brigadier General Farzad Esmaili, commander of the Islamic Revolutionary Guards Corps’ (IRGC) air defense force told state TV.

Iran and the six major powers reached a landmark nuclear deal in 2015 aimed at curbing Iran’s nuclear programme in exchange for lifting nuclear-related sanctions imposed on Tehran over its disputed nuclear work.

Enrichment of uranium at the Fordow facility, around 100 km (60 miles) south of Tehran, has stopped since the implementation of the nuclear deal in January.

Russia, under pressure from the West, in 2010 canceled a contract to deliver S-300s to Iran. But Russian President Vladimir Putin lifted that self-imposed ban in April 2015, after an interim deal was reached between Iran and the six powers.

In August, Iran said that Russia had delivered main parts of the system to the country, adding that the missile system would be completely delivered by the end of 2016.

The IRGC’s Esmaili did not say whether the system was operational, but added: “Today, Iran’s sky is one of the most secure in the Middle East”.

Iran’s top authority Supreme Leader Ayatollah Ali Khamenei said on Sunday that the country’s military power was for defensive purposes.

“The S-300 system is a defence system not an assault one, but the Americans did their utmost to prevent Iran from getting it,” Khamenei said in a speech broadcast live on state TV.