A Royal Navy submarine was authorized to surface close to a Russian ship "strictly as a deterrent measure," British Defense Secretary John Healey said.

The Royal Navy has been monitoring a Russian spy ship after it entered British waters, the defence secretary has told MPs. John Healey said the vessel, Yantar, was used for gathering intelligence and mapping the UK's critical underwater infrastructure. He said the incident was "another example of growing Russian aggression".

Britain said it monitored a Russian spy ship in the English Channel in recent days and would strengthen its response to secret operations by Russian ships and aircraft in an effort to protect undersea cables.

The UK authorized the British submarine to surface closely to the Russian vessel to warn it off, British defense secretary Healey said.

A Russian spy ship entered British waters twice in recent weeks, prompting the UK to deploy Royal Navy ships, Royal Air Force planes and a submarine, Defence Secretary John Healey said.

A British official sent a public warning to Russian President Vladimir Putin on Wednesday after the Royal Navy started tracking the Russian spy vessel Yantar in British waters this week.