Russia claimed on Wednesday that it prevented a Ukrainian attempt to take control of a drilling rig in the Black Sea.
The Defense Ministry in a statement said that it sank eight out of 14 boats used by Ukraine during the attempt on the Crimea-2, and that 80 Ukrainian servicemen were killed.
The statement added that the remaining six Ukrainian boats retreated.
It said the attempt was timed with the arrival of high-ranking U.S. and European representatives to Kyiv.
Earlier in the day, U.S. Secretary of State Antony Blinken and UK Foreign Secretary David Lammy arrived in Ukraine's capital to discuss continued support for Kyiv's defense in the ongoing war with Russia.
Ukrainian authorities have not yet commented on Russia's claim, and independent verification of the claim is difficult due to the ongoing conflict.
