The US has announced it is moving an advanced missile defence system to the Pacific island of Guam as North Korea steps up its warlike rhetoric.

A statement from Pyongyang said its military had been given final approval to launch a nuclear strike.

North Korea has threatened to target the US and South Korea in recent weeks.

Its statement came amid warnings from US Defence Secretary Chuck Hagel that North Korea was a "real and clear danger" to the US and its allies.

Speaking to Today presenter John Humphrys, John Everard, former UK Ambassador, explained that North Korea leaders "believe that they are the victim, they believe that they are being hounded by the United States".

He went on to speak of a "spiral of violence" between North Korea and the US and South Korea and said that war was "possible".

First broadcast on BBC Radio 4's Today programme on Thursday 4 March 2013.