Russia has delivered new anti-aircraft missile systems to Iran and will consider further requests by Tehran for defensive weapons.
Washington and Israel, who accuse Tehran of seeking to develop nuclear arms and undermining security in the region, have criticized the sale of TOR-M1 missiles. Tehran, they say, could use them against its neighbors.
"We have supplied the modern short-range anti-aircraft systems TOR-M1 in accordance with our contracts," Defense Minister Sergei Ivanov told reporters when asked about the sale.
"We're developing our military and technical cooperation with Iran in accordance with international law and will continue to develop it," he said. "And if Iran wants to buy defensive, I underline defensive, equipment for its armed forces then why not?"
Ivanov, who is also a deputy prime minister and is seen as a potential successor to President Vladimir Putin, did not say how many missile systems had been delivered or when the deliveries took place.
Russian arms sales and nuclear cooperation with Iran have strained relations with Washington, which suspects Tehran of using a nuclear power program as cover for development of atomic weapons.
Russia, building Iran's first nuclear power plant in Bushehr, says Tehran does not have the capability to make nuclear weapons. Iran says it has a right to develop its civilian nuclear sector and denies seeking nuclear arms.
Late last year Russia reluctantly joined U.N. sanctions against Iran, which introduced restrictions on Iran's trade in sensitive nuclear materials and technology, aimed at curbing Tehran's nuclear ambitions.
But Moscow says the sanctions do not apply to the missile systems, which are designed to shoot down aircraft, missiles and other weapons at medium and low altitudes.
"Iran is not under any sanctions," Ivanov said. "The U.N resolution that was accepted and for which the Russian Federation voted, does not apply to contracts made by Iran."
The Russian military insists that the missile systems will protect Iran from air attacks, but do not pose a threat to neighboring countries.
Russia dropped the idea of selling longer-range S300 anti-aircraft missiles to Iran last year, Russian news agencies have reported.
The U.S last year imposed sanctions on leading Russian arms firms over arms sales to Iran and Syria. One of the firms, Rosoboronexport, Russia's biggest arms exporter, is headed by an old colleague from Putin's KGB's past, Sergei Chemezov.