The United States says increasing military cooperation between Tehran and Moscow is a "concern," amid reports that Iran has delivered multiple shipments of ballistic missiles to Russia.
Reuters reported on February 21 that Iran had supplied Russia with hundreds of missiles through four shipments since January, with an unnamed Iranian military official quoted as saying that there "would be more in the coming weeks."
While Ukrainian and Western officials have yet to publicly confirm the Reuters report, the development is consistent with U.S. warnings.
A U.S. State Department spokesperson told RFE/RL that while they were not able to comment directly on the report, the increasing military cooperation between Iran and Russia "is something that should concern the entire world."
"We have been warning for some time that Russia was in negotiations with Iran to acquire close-range ballistic missiles and that those negotiations were actively advancing," the spokesperson said.
The spokesperson attributed Tehran and Moscow's improving relations to Russia becoming "more isolated" since it launched its full-scale invasion of Ukraine on February 24, 2022.
White House National Security Council spokesman John Kirby said at a briefing on February 22 that the United States would impose additional sanctions on Iran in the coming days for its efforts to supply Russia with drones and other technology for the war against Ukraine.
"We have not seen any confirmation that missiles have actually moved from Iran to Russia," Kirby said, but said that at the same time, "we have no reason to believe that they will not follow through."
Kirby also issued a warning to Iran that providing ballistic missiles to Russia for use against Kyiv would be met with even more sanctions and actions at the United Nations.
On February 20, an Iranian Defense Ministry spokesman insisted that his country's military cooperation with Russia "has nothing to do with the Ukraine war" and predated the conflict.
SEE ALSO: U.S. Slaps Sanctions On Iranian Firms, Individuals Involved In Drones, Revolutionary GuardFollowing its invasion of Ukraine, Russia was swiftly hit by a slew of Western sanctions, overtaking Iran as the most sanctioned country in the world in March 2022.
The two countries have grown close since the war started, expanding their economic and military cooperation.
Iran has been supplying Russia with its cheap but effective Shahed "kamikaze" drones, which Moscow has often used to target civilian infrastructure in Ukraine.
Iran has denied providing drones to Russia to use against Ukraine and insists that it sold a "limited number" of unmanned aerial vehicles (UAVs) to Moscow before the war. Russia has also rejected reports that it is using Iranian drones in the war.
However, the Russian Defense Ministry in July 2023 appeared to confirm in its monthly journal Armeisky sbornik that its Geran-2 drone is, in fact, the Iranian-made Shahed-136 UAV.
Reuters said Iranian shipments included the Fateh-110 and Zolfaqar short-range ballistic missiles.
This comes after UN curbs on Iran's imports and exports of missiles expired in October 2023, though Britain and the European Union said they would continue to impose the sanctions on Iran.
A month earlier, Russian Defense Minister Sergei Shoigu was shown around an Islamic Revolutionary Guards Corps (IRGC) weapons exhibition in Tehran by IRGC Aerospace Force commander Amir Ali Hajizadeh.
'Game Changer'
If confirmed, the delivery of Iranian missiles to Russia "would be a game changer, both militarily and politically," said John Krzyzaniak, a research associate at the Wisconsin Project on Nuclear Arms Control.
Missiles are harder to defend against than drones, allowing Russia to carry out more devastating attacks at long range.
Krzyzaniak added that the trade would give cash-strapped Iran a windfall and a reputational boost, as well as "a bargaining chip in its other dealings with Russia."
There have been reports over the past year about Tehran finalizing an agreement with Moscow to obtain Sukhoi Su-35 fighter jets to upgrade its aging air force. Observers have in the past suggested that one of Iran's objectives in supplying arms to Russia is to be able to acquire advanced warplanes.
Russia has started using North Korean missiles in the war with mixed results. However, Iran's short-range ballistic missiles have been battle-tested, says Nicole Grajewski, a fellow at Carnegie Endowment for International Peace's Nuclear Policy Program.
While the purported missile deliveries would further cement the growing military cooperation between Tehran and Moscow, it would be viewed as an escalation by the West, according to Grajewski.
"It would also be another nail in the coffin for the [Iran nuclear deal] and certainly would complicate any kind of parallel agreement on Iran's nuclear program -- even if those chances are dismal already," she added.