Iran admitted for the first time on Saturday that it has sent drones to Russia, but insisted they were supplied to its ally before the Russian invasion of Ukraine.
"We supplied Russia with a limited number of drones months before the war in Ukraine," Foreign Minister Hossein Amir-Abdollahian said, quoted by the official news agency IRNA.
Ukraine and its Western allies have accused Russia of using Iranian-made drones in recent weeks to carry out attacks in Ukraine. Tehran has repeatedly denied these claims.
Iran has repeatedly denied that it has been supplying arms to Russia for use in the Ukraine war.
"In a telephone conversation with the Ukrainian foreign minister last week, we agreed that if there was evidence (of Moscow's use of Iranian drones), he would provide it to us," Amir-Abdollahian said.
"If the Ukrainian side keeps its promise, we can discuss this issue in the coming days and we will take into account their evidence," he added.
The Iranian foreign minister again denied his country had supplied missiles to Russia, calling the accusations "completely false".
The Washington Post reported on October 16 that Iran was preparing to ship missiles to Russia.
Kyiv has said around 400 Iranian drones have already been used against the civilian population of Ukraine, and that Moscow has ordered around 2,000.
In response to these transfers, the European Union and United Kingdom have imposed sanctions on three Iranian generals and an arms firm accused of supplying Russia with drones.
In September, Kiev decided to significantly reduce diplomatic relations with Tehran because of alleged arms shipments to the country.