The possible sale of Russian air defense hardware to the Islamic Republic is a major irritant for both Israel and close ally the United States. Both have pressed Moscow not to go ahead with a deal that may help protect Iran's nuclear facilities from potential air strikes, Reuters reported on Sunday.
"There is a signed contract (to supply S-300 missiles) which we must implement, but deliveries have not started yet," Vladimir Nazarov, deputy secretary of Russia's Security Council secretary, told Interfax news agency in an interview.
"This deal is not restricted by any international sanctions, because the talk is about deliveries of an exclusively defensive weapon," he said.
Prime Minister Binyamin Netanyahu was due to hold talks with Russian President Dmitry Medvedev in Moscow on Monday, planning to push the Kremlin for urgent "crippling sanctions" against Iran over its nuclear program.