Iran summoned Ukraine's charge d'affaires in Tehran on Saturday after accusing the Ukrainian military of attacking an Iranian commercial vessel in the Caspian Sea, warning that the alleged strike that killed one sailor and injured another "will not go unanswered."
Ukraine's top diplomat in Tehran was called in by Manouchehr Moradi, Iran's assistant foreign minister and director general for Eurasia, who delivered a strong protest over the overnight attack.
Moradi called the strike a "criminal" act and said Iran would firmly defend its national security and interests, state media IRIB reported.
Earlier Saturday, Iran's Foreign Ministry accused Ukraine of attacking the commercial vessel in the Caspian Sea and condemned the alleged strike as an act of aggression.
The ministry urged the U.N. Security Council, the European Union and the wider international community to hold those responsible accountable.
Tehran also claimed the attack reflected Kyiv's continued "irrational and hostile approach" toward Iran, while reiterating that it has never intervened in the Russia-Ukraine conflict.
The ministry accused Ukraine of attempting to widen the war and spread insecurity, adding that Iran would defend its national security and interests under international law.
It warned that responsibility for any consequences would rest with Ukraine's leadership and its supporters.
Ukrainian President Volodymyr Zelenskyy said Ukraine had carried out long-range strikes against military and logistical targets supporting Russia's war effort.
In a statement on X, he said the overnight operation hit a weapons component plant in Kirov, an oil refinery in Tyumen, a logistics facility in Yekaterinburg and a fuel depot in Rostov-on-Don.
Zelenskyy also claimed Ukraine achieved "very strong results" in the Caspian Sea, including strikes on "vessels used in military cargo shipments involving Iran, as well as a warship."
Hours later, Zelenskyy accused Russia of expanding military cooperation with Iran and North Korea. He claimed Moscow has been providing Iran with satellite imagery of Gulf states and U.S. military facilities since early July, alleging the intelligence was later used in planning and assessing Iranian strikes.
Zelenskyy also alleged Russia is preparing to receive another 30,000 North Korean troops and additional ballistic missile launchers, describing the growing military cooperation among Moscow, Tehran and Pyongyang as a broader security threat beyond Ukraine.