A senior US defence official said the Russian missile cruiser Moskva, which sank in the northern Black Sea this week, was hit by at least one Ukrainian anti-ship missile, as claimed by the Kyiv government.
The Moskva was hit by one, and probably two, Neptune missiles on Wednesday, creating a large fire aboard, according to the official who spoke on condition of anonymity to discuss an intelligence assessment.
The Russians suffered some casualties aboard the ship, according to the official.
The Moskva is the biggest Russian warship damaged by enemy fire since 1941, when German dive bombers crippled Soviet battleship Marat in Kronshtadt harbour, according to military analysts.
Russian officials claimed the damage was caused by a fire on board, later claiming it sank as it was towed back to port in stormy weather after an explosion.
During the towing of the Moskva cruise ship to the port of destination, the ship lost its stability due to the damage caused by the detonation of ammunition. In the conditions of stormy seas, the ship sank, the Russian Defence Ministry said in a statement.
Pentagon officials said they could not confirm the Ukrainian claim, but they also did not refute it.
Last month, Ukraine said it had also destroyed a Russian landing support ship, the Orsk, on the smaller Sea of Azov.