MOSCOW (AP):  Russia will be ready to fire to hit intruding warships, a senior diplomat warned Thursday in the wake of a Black Sea incident in which a British destroyer sailed near Crimea in an area that Russia claims as its territorial waters.

Russia said one of its warships fired warning shots and a warplane dropped bombs in the path of British destroyer Defender on Wednesday to drive it away from the area near Sevastopol, but Britain denied that account and insisted its ship wasn't fired upon.

The incident marked the first time since the Cold War that Moscow acknowledged using live ammunition to deter a NATO warship, underlining the rising threat of military collisions amid Russia-West tensions.

Russia's Deputy Foreign Minister Sergei Ryabkov said Thursday that the inviolability of the Russian borders is an absolute imperative, adding that it will be protected by all means, diplomatic, political and military if needed.

He gibed that 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.

Asked what Russia would do to prevent such intrusions in the future, 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 in remarks carried by Russian news agencies. 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."

Russian President Vladimir Putin's spokesman deplored what he described as a "deliberate and well-prepared provocation by Britain and seconded the tough warning.

If unacceptable provocative actions are repeated, if those actions go too far, no options to legitimately protect the borders of the Russian Federation could be excluded, the spokesman, Dmitry Peskov, said in a call with reporters.

On Wednesday, the Russian Defense Ministry said a patrol ship fired warning shots after the HMS Defender had ignored a notice against intrusion and sailed 3 kilometres (1.6 nautical miles) into Russia's territorial waters near Sevastopol, the main Russian naval base in Crimea. It said a Russian Su-24 bomber also dropped four bombs ahead of the vessel to persuade the Defender to change course. Minutes later, the Defender left Russian waters, the ministry said.

Britain's Ministry of Defence denied the Defender had been fired on or was in Russian waters, but said it had been in Ukrainian waters.

No warning shots have been fired at HMS Defender, it said in a statement. The Royal Navy ship is conducting innocent passage through Ukrainian territorial waters in accordance with international law.

Russia annexed Ukraine's Crimean Peninsula in 2014, a move not recognised by most countries, gaining access to its long Black Sea coast. Russia has chafed at NATO warships visiting near Crimea as destabilising. In April, it declared a broader area off Crimea closed to foreign naval ships.

It's incorrect to say either that it was fired on or this ship was in Russian waters, Max Blain, a spokesman for Prime Minister Boris Johnson, said Wednesday. "HMS Defender was taking the most direct and internationally recognized route between Ukraine and Georgia.

He emphasised that Britain, and much of the international community, does not recognise Russia's annexation of Crimea.

The Russian navy chief, Adm. Nikolai Yevmenov, said that the British destroyer's move was clearly provocative and aimed to test Russia's resolve.

Our navy acted in a competent and safe manner to stop the provocation, he told reporters in St Petersburg.