Israel on Monday warned that Russia’s decision to lift its five-year ban on the delivery of S-300 air-defense missile system to Iran proves that the deal to curb Tehran’s nuclear program will only strengthen it militarily.

“Instead of demanding that Iran desist from the terrorist activity that it is carrying out in the Middle East and throughout the world, it is being allowed to arm itself with advanced weapons that will only increase its aggression,” Strategic Affairs Minister Yuval Steinitz said on Monday.

The Kremlin said Russian President Vladimir Putin signed a decree ending a self-imposed ban on delivering the S-300 missile system to Iran, removing a major irritant between the two, after Moscow canceled a corresponding contract in 2010 under pressure from the West.

The United States and Israel had lobbied Russia to block the missile sale before it did so in 2010, saying the S-300 system could be used to shield Iran’s nuclear facilities from possible future air strikes.

US Secretary of State John Kerry spoke by telephone with Russian Foreign Minister Sergey Lavrov on Monday to express his concern about the shipment of S-300 missiles to Iran.

The two men also talked more globally about the framework agreement between the six world powers and Iran, which was negotiated earlier this month in Lausanne, Switzerland.

Lavrov told the Russian News Agency TASS that the S-300 ban is no longer necessary in light of the framework agreement.

He added that the system is defensive, hence would pose no threat to Israel.

“We see no need to continue doing this given progress in talks on Iran’s nuclear program and the absolutely legitimate nature of the forthcoming deal,” he said.

“S-300 is an air-defense missile system, which is of a purely defensive nature. It is not designed for attacks and will not put at risk the security of any regional state, including Israel,” Lavrov said.

But US State Department spokeswoman Marie Harf told reporters in Washington, “It is not constructive at this time for Russia to move forward with this. Given Iran’s destabilizing actions in the region… this is not the time to be selling those kind of systems to [Iran].”

Harf pledged that the US would protect its allies in the region, including Israel, against Iran.

She added that the US does not believe the decision would impact the continued negotiations between the six world powers and Iran toward a final agreement by the end of June.

“We see this as separate from the negotiations,” Harf said.

Steintiz disagreed and said that Russia’s decision to lift the ban is a sign of how dangerous the Iran deal was.

“This is the direct result of the legitimacy that Iran is receiving from the nuclear deal being made with it. This also proves that the economic momentum in Iran that will come in the wake of the lifting of the sanctions will be exploited for armaments and not used for the welfare of the Iranian people,” he said.

The US has said that this deal will make the region safer, because it will curb Iran’s nuclear program by extending its breakout time to develop nuclear weapons from a few months to a year’s time.

In a phone conference with Israeli reporters earlier in the day, Under Secretary of State for Political Affairs Wendy Sherman – who heads the US negotiating team in the Iran talks – said that a military strike against the Islamic Republic would not eliminate its nuclear program, rather only set it back by a few years.

She argued that the framework agreement is therefore the best option to keep Iran from producing nuclear weapons for an extended period of time.

Israel has argued that the best option is continued and increased sanctions.

On Monday night Prime Minister Benjamin Netanyahu warned of what would happen with Iran once sanctions were lifted when he spoke at an Israel Police ceremony in Beit Shemesh.

“Iran is receiving legitimacy to continue these actions and when the sanctions are lifted shortly, if indeed the deal is approved, it will receive billions of dollars to finance its war and terrorism machines, with international legitimacy.

Before our very eyes an absurd reality is taking shape in which the key to our fate and the future of the Middle East is liable to be delivered into the hands of the fanatical Iranian regime,” he said.

“An agreement full of holes with Iran will not ensure regional stability; a vigorous and resolute policy that prevents it from arming itself with nuclear weapons and compels it to halt its takeover of other nations would,” Netanyahu added.

Russia’s lifting of the S-300 anti-missile ban was not the only Iranian restriction that it lifted.

A senior Russian government official said separately that Moscow has started supplying grain, equipment, and construction materials to Iran in exchange for crude oil under a barter deal.

Sources told Reuters more than a year ago that a deal worth up to $20 billion was being discussed and would involve Russia buying up to 500,000 barrels of Iranian oil a day.

Officials from the two countries have issued contradictory statements since then on whether a deal has been signed, but Deputy Foreign Minister Sergei Ryabkov said on Monday one was already being implemented.

“I wanted to draw your attention to the rolling out of the oilfor- goods deal, which is on a very significant scale,” Ryabkov told a briefing with members of the upper house of parliament on the talks with Iran.

“In exchange for Iranian crude oil supplies, we are delivering certain products. This is not banned or limited under the current sanctions regime.”

He declined to give further details. Russia’s Agriculture Ministry declined comment and the Energy Ministry did not respond to request for comment. There was no comment from Iran.

Iran is the third largest buyer of Russian wheat, and Moscow and Tehran have been discussing the oil-for-goods barter deal for more than a year.

Ryabkov suggested Russia had high hopes that its steady support for Iran would pay off in energy cooperation once international sanctions against Tehran are lifted.

“It takes two to tango. We are ready to provide our services and I am sure they will be pretty advantageous compared to other countries,” he said. “We never gave up on Iran in a difficult situation… Both for oil and gas, I think the prospects for our cooperation should not be underestimated.”

He also reiterated Moscow’s view that an arms embargo on Iran should be lifted once a final nuclear deal is sealed.

Sanctions have cut Iran’s oil exports to about 1.1 million barrels per day from 2.5 million in 2012.

Analysts say Iran is unlikely to see a major boost in exports before next year.

One upper house lawmaker asked Ryabkov whether lifting sanctions on Tehran could undermine Russia’s position on global energy markets, including as the main gas supplier to Europe.

“I am not confident as yet that the Iranian side would be ready to carry out supplies of natural gas from its fields quickly and in large quantities to Europe. This requires infrastructure that is difficult to build,” he said.

Leonid Ivashov, a retired Russian general who now heads the Moscow- based Center for Geopolitical Analysis think tank, said the move is part of a race for future contracts in Iran.

“If we now delay and leave Iran waiting, then tomorrow, when sanctions are fully lifted, Washington and its allies will get Iran’s large market,” RIA news agency quoted him as saying.

Reuters contributed to this report.