Russia said it had fired warning shots at the Defender, and later threatened to bomb British naval vessels in the Black Sea if there were further "provocative" actions off Crimea, which Russia annexed from Ukraine in 2014. The peninsula is still recognized internationally as part of Ukraine.
The Defender's commander, Vince Owen, said the British navy was committed to "providing reassurances and security in the region, and incredible deterrence to those who seek to undermine global security."