The European Union on Wednesday prepared new sanctions against Iran over its supply of drones to Russia, as the UN Security Council met on the unmanned strikes that devastated Ukraine.

The United States, France and Britain called on the Security Council’s closed discussion to sound alarm over the drone shipments, which Western officials say violate a UN resolution, despite Russia having a veto to block any new sanctions offer.

Ukraine has for weeks reported attacks by Russia using Iranian Shahed-136 drones – unmanned aerial vehicles whose warheads detonate in kamikaze attacks – and has sought to sever ties with Tehran.

Iran and Russia have both denied using the drones, with Tehran saying it wants talks with Ukraine. But the European Union said on Wednesday it had confirmed Iran supplied the drones to Russia.

Nabila Massrali, spokeswoman for EU foreign policy chief Josep Borrell, said the bloc had “collected our own evidence” and would prepare “a clear, swift and decisive EU response”.

A list viewed by AFP showed the bloc was planning sanctions on three senior military officials, including General Mohammad Hossein Bagheri, the chief of staff of the Iranian Armed Forces.

The sanctions, which are due to be approved before an EU summit in Brussels on Thursday, would also hit drone maker Shahed Aviation Industries, an aerospace company linked to the powerful Revolutionary Guards.

Ukraine’s military said on Wednesday it shot down more than 220 Iranian-made drones in just over a month, although drone fire on the capital Kyiv on Monday killed five.

The United States said the Security Council will hear from an expert about the transfer of the drones, officially known as unmanned aerial vehicles.

“We have seen over the past month that there is ample evidence that Russia is using UAVs from Iran in cruel and premeditated attacks against the people of Ukraine,” State Department spokesman Vedant Patel told reporters in Washington .

“We will express serious concerns about Russia’s acquisition of unmanned aerial vehicles from Iran in clear violation of UN Security Council Resolution 2231.”

The 2015 resolution blessed a now ailing nuclear deal.

The resolution’s ban on Iran’s sale of conventional arms expired in 2020, despite attempts by Donald Trump’s then US administration.

The United States has not spelled out how Iran would violate it, but the resolution continues to ban all transfers that could benefit nuclear-capable ballistic missiles until October 2023, unless authorized by the Security Council.

The alleged arms transfers come as Iran comes under mounting pressure over its crackdown on the most widespread protests in years sparked by the death of Mahsa Amini, a 22-year-old arrested by the clerical state’s notorious “morality police.” stands.

The unrest has sparked new Western human rights sanctions and sidelined US President Joe Biden’s efforts to restore the 2015 nuclear deal from which Trump pulled the United States.

Western officials have highlighted the Iranian drones as evidence that Russia, historically one of the world’s largest arms exporters, has severely depleted its arsenal from battlefield casualties.

The United States has released information that says Iran’s drones have frequently failed and that Russia has also approached North Korea, despite China reportedly rejecting calls for arms supplies.

Estonian Defense Minister Hanno Pevkur, on a visit to Washington, said Russia relies on drones, both because of low supplies and Ukraine’s success in the sky.

The Russians “understand that they do not have supremacy in the air at the moment because there is air defense from the Ukrainian side. They’ve already lost a lot of planes,” Pevkur told reporters.