As reported by Censor.NET citing The Mirror, British Defence Secretary Michael Fallon said today.
"In the most extreme circumstances we've made it very clear that you can't rule out the use of nuclear weapons as a first strike," Fallon said.
The comments come after weeks of tension between the West and North Korea - which has warned it will "wipe America off face of the Earth".
The confirmation was squeezed out of Mr Fallon as he was interviewed about the rival Labour Party - whose leader ducked questions over whether he would pull the nuclear 'trigger.'
Fallon could not say what those circumstances would be for him.
"They are better not specified or described, which would only give comfort to our enemies and make the deterrent less credible.
"The whole point of a deterrent is you've got to leave uncertainty in the mind of anybody who might be thinking of using weapons against this country," the defense secretary said.