Ukrainian forces struck an Iranian vessel transporting military cargo between Iran and Russia in the Caspian Sea, Ukraine's security service (SBU) said on July 25.President Volodymyr Zelensky wrote on social media that Kyiv's forces "achieved very good results from long-range strikes in the waters of the Caspian Sea," reporting early morning strikes on an unspecified number of vessels, including a ship "transporting military cargo in cooperation with Iran."The SBU confirmed that the vessel, which was operating while evading international sanctions, shipped military cargo between the two countries.Iran's Foreign Ministry later claimed the strike targeted a commercial vessel, killing one sailor and injured another. The Kyiv Independent cannot verify claims made by Iranian officials. The full extent of the damage caused was not immediately clear.Tehran, a key ally of Moscow, condemned the strike as "an act of aggression that could further inflame and expand the flames of war." Ukraine's chargé d'affaires in Tehran was summoned in protest."It is clear that responsibility for the consequences arising from the adventurism of the head of the Ukrainian regime will rest with that regime and its supporters and instigators," the Iranian Foreign Ministry said following the strike.Russia and Iran have deepened cooperation in recent years, particularly during Moscow's war against Ukraine, with Tehran supplying drones and other military equipment used by Russian forces. Russia regularly launches hundreds of Shahed-type drones in mass nightly attacks against Ukrainian cities. The Ukrainian strike comes as Iran continue to be embroiled in its own conflict with the United States. In his evening address, Zelensky did not address the strike but said that Moscow has been coordinating with Tehran to provide satellite imagery of U.S. and Gulf military installations amid the U.S.-Iran war. "Since the beginning of July, we have recorded active Russian satellite surveillance of the Gulf states and U.S. military facilities located there. These images subsequently appear in Iran," Zelensky said."There is a clear correlation between Russia’s satellite imagery of these sites and Iranian strikes – both before the attacks, in preparation for them, and afterward, to assess the damage inflicted. On July 19 and 20 alone, four air bases fell within the area of interest of Russian satellites – two in Bahrain, one in Jordan, and one in Kuwait," the president added. Zelensky comments come days before he is reportedly scheduled to meet with U.S. President Donald Trump in Washington next week.