Amid bitter squabbles over Iran's quest for acquiring the advanced S-300 air defense system, Russian Deputy Prime Minister Sergei Ivanov says no such missile has so far been delivered to Iran.

In reaction to Israeli rhetoric against Tehran, Iran has opted to acquire the sophisticated S-300 defense system — which, according to Western experts, would rule out the possibility of an Israeli airstrike on Iranian nuclear sites.

While a deal has been negotiated between Tehran and Moscow over the S-300 system since 2007, neither side has so far issued an official confirmation on the delivery of the system to Iran.

When asked about the timing of the delivery of the defense system to Iran, Ivanov, who oversees the defense sector in the Russian government, told reporters, "There have been no such deliveries to date."

The remarks by the Russian official comes as earlier in September, Israeli Prime Minister Benjamin Netanyahu made a secret visit to Moscow during which he is believed to have discussed measures to hold off on providing the ultramodern missiles to Iran with Russian leaders.

Israeli officials have on many occasions expressed alarm over the possibility of the system being delivered to Iran.

"The S-300 is a Russian-made surface-to-air missile system that is very advanced, with long ranges and many capabilities," Israeli Air Force (IAF) commander, Major General Ido Nehushtan said earlier in September.

"We need to make every effort to stop this system from getting to places where the IAF needs to operate or may need to operate in the future," he added.

The S-300 surface-to-air missile system, which can track targets and fire at aircraft 120 km (75 miles) away, features high jamming immunity and is able to simultaneously engage up to 100 targets.

Addressing the issue earlier in August, Israeli President Shimon Peres explained that the Kremlin had made a promise to reconsider the planned delivery of the S-300 missiles to Iran.

"President [Dmitry] Medvedev gave a promise he will reconsider the sales of S-300s because it affects the delicate balance which exists in the Middle East,'' Peres told reporters.

Israel has repeatedly threatened to strike Iran's nuclear facilities, — including the uranium enrichment plant at Natanz or the country's first atomic power plant, which has been under construction by Russian workers in Bushehr for years — arguing that the country's nuclear activities are an existential threat to Tel Aviv's security.

This is while Tehran says its nuclear program is aimed at the civilian applications of the technology and has called for the removal of weapons of mass destruction from across the globe.

CS/HGH