Russia's Vladimir Putin has SLOT XO accused the UK and US military of staging a "complex provocation," after British warship HMS Defender sailed near the coast of Russian-annexed Crimea.
While there was no risk of starting World War Three, he said, he believed it was part of an attempt to set up military bases in or near Ukraine.
President Putin alleged a US spy plane was part of the operation too.
The Royal Navy rejected the Russian account of what happened on 23 June.
BBC correspondent Jonathan Beale, on board HMS Defender at the time, said it had been buzzed by Russian warplanes and coastguard vessels had threatened to open fire on the ship. While some firing had taken place, he said it was well out of range.
Reiterating the navy's explanation, Prime Minister Boris Johnson's spokesman said on Wednesday that the destroyer "was conducting innocent passage through Ukrainian territorial waters in accordance with international law".
A separate encounter in the Black Sea has since been reported the following day by the Dutch navy, which has accused Russian fighter jets of repeatedly harassing its ship, HNLMS Evertsen.