The denial comes as the Czech republic, which holds the European Union's rotating presidency, announced that the bloc had agreed sanctions against three individuals and one entity alleged to have supplied Iranian attack drones to Russia for use against Ukrainian targets.

Citing US and allied security officials, the Washington Post reported Sunday that Tehran also planned to send Iranian surface-to-surface missiles to Russia.

"During a telephone conversation with (EU foreign policy chief) Josep Borrell, I told him that our politics... is that we are opposed to the war and its escalation in Ukraine," Iran's Foreign Minister Hossein Amir-Abdollahian said on Twitter on Thursday.

"The allegation of sending Iranian missiles to Russia for use against Ukraine is without foundation."

"We have cooperation in defence matters with Russia, but it is certainly not our politics to send arms and drones against Ukraine," Amir-Abdollahian added.

Last month, Kyiv decided to significantly reduce its diplomatic relations with Tehran over alleged arms deliveries to Russia.

Moscow on Wednesday warned the United Nations not to probe alleged strikes by Iranian-made drones in Ukraine, joining Tehran in denying the weapons' alleged origin.

Ukraine had asked the EU on Monday to impose more sanctions against Iran after several strikes by attack drones against the capital Kyiv that killed at least three people.

The EU sanctions target Shahed Aviation Industries -- a firm allegedly linked to Iran's Islamic Revolutionary Guards Corps -- and three military officials, including the chief of staff of Iran's armed forces, Major General Mohammed Hossein Bagheri.

Tehran had on Tuesday said it was ready for talks with Kyiv to clarify "baseless" claims surrounding drones and other weapons.