Iranian missiles
Motorists and pedestrians pass a billboard depicting Iranian missiles in Tehran, Iran, on April 20, 2024. ATTA KENARE/AFP via Getty Images

American and European officials believe Iran has delivered hundreds of short-range ballistic missiles to Russia as it steps up aerial attacks against Ukraine that have killed dozens of civilians recently.

Multiple news outlets on Saturday confirmed a report by the Wall Street Journal report about the transfer, which followed months of White House warnings to Tehran against sharing the deadly weapons.

"Any transfer of Iranian ballistic missiles to Russia would represent a dramatic escalation in Iran's support for Russia's war of aggression against Ukraine and lead to the killing of more Ukrainian civilians," National Security Council spokesperson Sean Savett said in a statement.

"This partnership threatens European security and illustrates how Iran's destabilizing influence reaches beyond the Middle East and around the world."

Iran denied transferring the missiles and said it "considers the provision of military assistance to the parties engaged in the conflict — which leads to increased human casualties, destruction of infrastructure, and a distancing from ceasefire negotiations — to be inhumane," according to the Associated Press.

"Thus, not only does Iran abstain from engaging in such actions itself, but it also calls upon other countries to cease the supply of weapons to the sides involved in the conflict," Iran's mission to the United Nations said in a prepared statement.

The Russian Embassy in Washington didn't respond to a request for comment, according to the Journal.

The shipment involved a few hundred short-range missiles with ranges of up to around 500 miles, the Journal said Friday, citing unidentified Western officials.

A senior European official reportedly warned that Iran was expected to continue sending arms to Russia.

"This is not the end," the official told the Journal.

It's unclear when the missiles were delivered but Ukrainian President Volodymyr Zelenskyy said his country urgently needed more air defense systems during a Friday meeting of the Ukraine Defense Contract Group at the U.S. Ramstein Air Base in Germany.

Russian efforts to acquire the Iranian weapons date to at least September 2023, when then-Russian Defense Minister Sergei Shoigu traveled to Tehran to inspect the Islamic Revolutionary Guard Corps' short-range Ababil missile and other missile systems.

Last month, Reuters reported that dozens of Russian military personnel were being trained in Iran to use the satellite-guided Fath-360 short-range missile system, citing two European intelligence sources.

The sources said Russian defense ministry officials were believed to have signed a contract in Tehran on Dec. 13 to acquire the Fath-360 and Ababil missile systems.

European officials said Friday that they were working with the U.S. to respond with sanctions that have been in the works since the summer, the Journal said.

The punishment is likely to include banning Iran Air from flying to European airports and targeting Iranian businesses and people involved in the missile transfers, according to the Journal.