• Ukraine successfully attacked a Russian submarine using underwater drones for the first time.
• The strike occurred in Novorossiysk, damaging a Kilo-class submarine known for launching Kalibr missiles.
• This attack represents a significant escalation in Ukraine's naval combat capabilities.
• Russia has denied any damage occurred to its submarine fleet following the strike.
• The operation highlights ongoing tensions amid diplomatic negotiations involving U.S. officials.

Ukraine has conducted a pioneering underwater drone strike against a Russian Kilo-class submarine stationed in Novorossiysk, according to the Security Service of Ukraine (SBU). This operation utilized the "Sub Sea Baby" drones, marking a significant advancement in Ukraine's use of unmanned vehicles for naval combat. The SBU reported that the submarine suffered critical damage and was effectively knocked out of operation, a statement it supported with footage showing a strong explosion near the vessel at the port pier, as confirmed by Reuters and South China Morning Post.

About the striking operation, Ukrainian officials have made claims that this constitutes the first successful underwater drone assault on a submarine. Alexander Kamyshin, an advisor to President Zelensky, highlighted this historic moment on social media. Despite these claims, Russia's Black Sea Fleet denied any damage report, asserting that all vessels remained operational and undamaged, as noted by Business Insider and Reuters.

The attack came during a heightened diplomatic climate, as U.S. negotiations over the conflict continue. Ukraine is striving to assert its military capabilities, especially after President Trump remarked that President Zelensky "did not have the cards" in the ongoing discussions. The Ukrainian navy spokesperson, Dmytro Pletenchuk, emphasized that the operation marked a "turning point" in the naval conflict with Russia, challenging previous perceptions about naval engagements in the war, according to Al Jazeera and South China Morning Post.

Moreover, the Kilo-class submarine, capable of carrying multiple Kalibr missile launchers, had been relocated to Novorossiysk—Russia's primary remaining Black Sea base—following earlier Ukrainian naval operations that pushed parts of the Russian fleet away from Crimea. This submarine attack indicates Ukraine's ongoing efforts to disrupt Russian military operations and infrastructure as it continues to advance its drone and missile capabilities against naval targets, supported by Reuters, Al Jazeera, and South China Morning Post.