MOSCOW — President Vladimir Putin on Monday lifted a ban on supplying Iran with sophisticated S-300 air defense missile systems after Tehran struck a landmark framework deal with the West over its nuclear program.

A decree signed by Putin gave the go-ahead for "the shipment from Russia to Iran," ending Moscow's self-imposed ban on supplying the surface-to-air missiles to the Islamic republic.

The move comes before any sanctions have been lifted on Iran, with difficult technical negotiations still to come following a breakthrough April 2 deal aimed at curbing Tehran's nuclear drive.

Russia's decision to proceed with the delivery sparked strong condemnation from Israel and triggered concern in Washington.

But Iran hailed the move as a step towards "lasting security" in the region, the country's Defence Minister Hossein Dehqan was quoted as saying by state news agency IRNA.

Moscow had blocked deliveries of the to Tehran in 2010 after the United Nations slapped sanctions on Iran over its nuclear program barring hi-tech weapons sales.

Iran then filed a $4-billion suit at an arbitration court in Geneva for the cancellation of the $800 million order by Russia, which has long been Iran's principal foreign arms supplier.

Russian Foreign Minister Sergei Lavrov on Monday insisted the missile deliveries were not covered by the earlier UN sanctions and that the progress in the nuclear talks between Iran and six world powers meant there was no longer any need for Russia to maintain the ban.

He said the missile system was "exclusively defensive" and did not pose a threat to Iran's foes.

Washington said US Secretary of State John Kerry raised his concerns about the end of the sales ban on the S-300 missile system directly with his Lavrov in an early morning phone call.

"We don't believe it's constructive at this time for Russia to move forward with it," said State Department acting spokeswoman Marie Harf.

"We think given Iran's destabilizing actions in the region, in places like Yemen or Syria or Lebanon, that this isn't the time to be selling these kinds of system to them," Harf told reporters.

The US military also criticized Russia's announcement. "Our opposition to these sales is long and public. We believe it's unhelpful," Pentagon spokesman Col. Steve Warren told reporters.

'Nothing is Binding'

The framework nuclear deal agreed in Lausanne this month marked a crucial advance in a 12-year standoff between Iran and the West, which disputes Tehran's denial that it is seeking to build a nuclear bomb.

World powers must resolve a series of contentious issues by a June 30 deadline for a final deal, including the steps for lifting global sanctions imposed on Iran, and lingering questions over the possible military dimensions of its nuclear program.

Iran's Supreme leader Ayatollah Ali Khamenei, who will have the final say on any deal, has plunged the accord into doubt suggesting that "nothing is binding" while President Hassan Rouhani demanded that sanctions be immediately lifted when any deal is signed.

Global powers Britain, China, France, Germany, Russia and the US have said sanctions will only be gradually eased and want a mechanism to ensure they can be swiftly reimposed if Iran breaks its word.

Perceived 'Legitimacy'

While not the most sophisticated of Russia's missile systems, the S-300 would bolster Iran's defenses against any attack on its nuclear sites.

Neither Israel nor the United States have ruled out air strikes if Tehran pursues what Western powers fear is a bid to develop a nuclear bomb.

Israel — which strongly opposed the initial missile deal — lashed out at Russia's decision, saying it was proof that the Iranians were using the nuclear deal to arm themselves.

"This is a direct result of the legitimacy that Iran is receiving from the nuclear deal that is being prepared, and proof that the Iranian economic growth which follows the lifting of sanctions will be exploited for arming itself and not for the welfare of the Iranian people," Israeli Intelligence Minister Yuval Steinitz said in a statement.

Despite the dispute over the S-300 missiles, Moscow and Iran have remained on good terms, with Russia agreeing to build new nuclear reactors for Tehran and both sides supporting President Bashar al-Assad in Syria.

During a visit by Russian Defence Minister Sergei Shoigu to Tehran in January, Iranian military officials said the two sides had "decided to settle the S-300s problem."

Russia's state arms company said in February that it had offered to supply Iran with Antey-2500 missiles, an upgraded version of the S-300 air defense system that figured in the previous contract.

As Russia has been hit by Western sanctions over its involvement in the conflict in Ukraine, it has stepped up its economic ties with Iran in the past year.