British Prime Minister Boris Johnson on Thursday said it was "entirely right" for a British warship to travel through the waters off Crimea amid an ongoing diplomatic spat with Russia.

Moscow has threatened to drop bombs on foreign vessels that enter waters close to the territory annexed from Ukraine in 2014.

Johnson said Britain would defy the Kremlin, insisting that it was "entirely right" to "pursue freedom of navigation in the way that we did."

"I think it was wholly appropriate to use international waters, and, by the way, the important point is that we don’t recognize the Russian annexation of Crimea," he said in televised remarks.

Johnson's comments came after Russia claimed yesterday that one of its coast guard patrol vessels had fired warning shots at the British destroyer HMS Defender.

Moscow also said that one of its warplanes had dropped four bombs near the Royal Navy warship to force it to leave the area.

UK's top diplomat hits out at Russian accusations

British authorities disputed Moscow's account of the incident.

"No shots were fired at HMS Defender," UK Foreign Secretary Dominic Raab told reporters in Singapore during a visit to discuss trade deals. 

"The Royal Navy ship was conducting innocent passage through Ukrainian territorial waters. We were doing so in accordance with international law and the Russian characterization is predictably inaccurate."

The incident marked the first time since the Cold War that Russia acknowledged using live ammunition to deter a NATO warship.

Russia warns Britain over 'provocation'

The Kremlin's official spokesman, Dmitry Peskov, said they believed Britain's action was "a deliberate and premeditated provocation."

"In the event of a repeat of unacceptable provocative action — if those actions go too far, no options can be ruled out in terms of legally defending Russia’s borders," Peskov told reporters.

Russia's Deputy Foreign Minister Sergei Ryabkov said the British navy should rename its destroyer from Defender to Aggressor and warned that "those who try to test our strength are taking high risks.''

Ryabkov told reporters it would stand ready to fire on targets if warnings don't work.

"We may appeal to reason and demand to respect international law,'' Ryabkov said, the Russian Interfax news agency reported. "If it doesn't help, we may drop bombs and not just in the path but right on target if colleagues don't get it otherwise."

Russia has said that NATO warships sailing near Crimea are destabilizing to the region. In April, it unilaterally declared a broader area of Crimea closed to foreign naval ships.

lc/sms (AP, Reuters)