Iran says it gave drones to Russia in the months before Moscow invaded Ukraine, backtracking on previous claims it never supplied weapons to Russia.
Tehran provided a "small number of drones" to Russia in the months before the war, Foreign Minister Hossein Amirabdollahian said in comments published by state-affiliated outlets. Iran had previously refuted growing evidence it had sent drones and other weapons to Moscow.
Mr Amirabdollahian denied that Iran had also sent missiles to Moscow and said Tehran will "react" if it is proven Iranian drones have been used by Russia in Ukraine.
An army spokesperson later claimed that Iran is "not involved" in the war.
Ukraine and its western allies say Tehran sent drones to support Russia's offensive. The EU and US have stepped up sanctions on Iran over its material support for Moscow.
Foreign ministry spokesman Oleg Nikolenko warned Iran following Moscow's admission.
"Tehran should realise that the consequences of complicity in the crimes of the Russian Federation's aggression against Ukraine will be much greater than the benefit of Russia's support," he wrote on Facebook.
President Volodymyr Zelenskyy recently vowed to take down Iranian-made Shahed kamikaze drones, which have been deployed in multiple offensives on Ukraine, including on strikes in the centre of Kyiv.
Speaking next to a downed Shahed drone, Mr Zelenskyy promised to "clip the wings" of Moscow's air power.
Ukraine's air force said it has downed more than 300 Iranian drones, while the US said Tehran has sent drone trainers to occupied areas of Ukraine.