Russian President Vladimir Putin warned on Sunday his country’s navy can launch an “unpreventable strike” if needed.
His warning comes just weeks after a British warship sailed through waters off Crimea, angering Moscow.
Putin addressed the crowd at a navy parade in St Petersburg on Sunday, "The Russian Navy has everything they need for the guaranteed defence of the motherland and our national interests. We are capable of detecting any underwater, above-water, or airborne enemy and, if required, carry out an unpreventable strike against it."
Putin’s speech follows an incident in the Black Sea in June.
Russia said it fired warning shots and had dropped bombs in the path of a British warship to chase it out of the Crimea peninsula.
Britain rejected Russia’s account of the incident.
Instead, the UK said Russia fired during a pre-announced “gunnery exercise” and no bombs had been dropped.
Russia annexed Crimea from Ukraine in 2014, and the Kremlin says the warship entered its territorial waters, but Britain and most of the world say the waters belong to Ukraine.