The United Kingdom has confirmed that one of its Royal Navy nuclear-powered submarines surfaced close to the Yantar, a notorious Russian spy ship late last year, to make it clear it was being observed.

In a message to Vladimir Putin, Defence Secretary John Healey said ‘we see you, we know what you are doing and we will not shy away from robust action to protect this country’

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