NBC says "The attack happened after Ukrainian forces asked the Americans about a ship sailing in the Black Sea south of Odesa, U.S. officials told NBC News. The U.S. identified it as the Moskva, officials said, and helped confirm its location, after which the Ukrainians targeted the ship."
Slightly different version. The US confirmed things the Ukrainians knew, also providing the ship's name. Sounds like the Ukrainians were checking it was a good target to avoid a possible mistake. Much less damaging claim.