Tehran requested documents from Kiev documenting and proving Russia's usage of Iranian drones in Ukraine as part of the ongoing war, Iranian Foreign Minister Hossein Amir-Abdollahian said on Wednesday.

Amir-Abdollahian and Croatian Minister of Foreign and European Affairs Gordan Grlić-Radman had a phone conversation that saw the two discussing bilateral ties between their countries and Iran's stance on the ongoing war.

"We are strongly against the war and arming each side of the war. We have told the Ukrainian authorities to provide any evidence about the use of alleged Iranian drones in the Ukraine war," the Iranian top diplomat told his Croatian counterpart.

On the other hand, Amir-Abdollahian did not rule out that Tehran had cooperated with Russia in the defense sector for years, but "we did not support the war against Ukraine and we did not provide any of the Iranian weapons to Russia for use in the war against Ukraine."

The US accuses Iran of supplying Russia with drones for use in the war in Ukraine, an accusation Tehran consistently denies. Just earlier this month, Amir-Abdollahian strongly denied Iran's sale of drones and weapons to Russia for use in the war in Ukraine, stressing that the Islamic Republic of Iran "supports the political solution to the crisis in Ukraine." 

However, while US National Security Advisor Jake Sullivan accused Iran of selling unmanned drones to Russia which he argued would pose a threat if used in Ukraine, he stated on July 13 that the US has no evidence of such trade between the two nations.

"Anyone doing business with Iran that could have any link to UAVs or ballistic missile developments or the flow of arms from Iran to Russia should be very careful and do their due diligence - the US will not hesitate to use sanctions or take actions against perpetrators," State Department Spokesperson Vedant Patel told reporters on Monday.

Iranian drones started to fly over Ukraine for the first time a few weeks ago. The drones flew from Crimea, according to Andriana Arekhta, a first sergeant in the Ukrainian armed forces, and headed to attack a special forces unit fighting near the southern city of Kherson.

Allegedly, Russia is chiefly using the Shahed-136/Geran-2 type kamikaze drone against Ukraine, with many reports surfacing about the matter in recent days. 

The Russian armed forces have been conducting a vicious campaign over the past few days, which has seen Moscow shelling Ukraine and carrying out drone strikes, causing air raid sirens to blare throughout the country, and leading to a highly tense atmosphere.

Russia carried out over the past weeks strikes against infrastructure critical for the Ukrainian military, which happened to include facilities related to energy and connectivity.

On Tuesday, Ukrainian President Volodymyr Zelensky claimed that Russia was deploying almost 2,500 attack drones purchased from Iran.