The EU has agreed sanctions against three individuals and one entity supplying Iranian drones to Russia that have been used to bomb Ukraine, the EU's Czech presidency said on Thursday.

"After 3 days of talks, EU ambassadors agreed on measures against entities supplying Iranian drones that hit Ukraine," the presidency said on Twitter.

The sanctions will come into force on Thursday.

"EU states decided to freeze the assets of 3 individuals and 1 entity responsible for drone deliveries," the presidency said.

"The EU is also prepared to extend sanctions to 4 more Iranian entities that already featured in a previous sanctions list," it said.

Ukraine accused Russia of using four Iranian-made drones to bomb Kyiv on Monday and said its air defences have shot down 223 Iranian drones since mid-September.

The Kremlin says it has no knowledge of its army using Iranian drones in Ukraine and Tehran has said the claims that it is providing Russia with weapons are "baseless".

European Council chief Charles Michel welcomed the move as he prepares to host the 27 EU leaders at a summit in Brussels this week.

"We take swift action against Iran who supports Russia's war in Ukraine," he said.

A Ukrainian serviceman watches the sky during a drone attack in Kyiv on October 17, 2022. Photo: AFP

Czech Prime Minister Petr Fiala said the sanctions were "aimed at the persons and entities that manufacture and supply the drones".

"This is our clear response to the Iranian regime providing Russia with drones, which it uses to murder innocent Ukrainian citizens," he said.