BUILD-UP TO WW3 - North Korea Advises Citizens To Leave Border Region

North Korea says it is scrapping all non-aggression pacts with South Korea, closing its hotline with Seoul and shutting their shared border point.

The announcement follows a fresh round of UN sanctions punishing Pyongyang for its nuclear test last month.

Earlier, Pyongyang said it had a right to carry out a pre-emptive nuclear strike and was pulling out of the armistice that ended the Korean War.

The US said "extreme rhetoric" was not unusual for Pyongyang.

China, which is the North's only major ally, called for both North and South to show restraint and to continue talking.

Beijing rarely criticises its ally, but has criticised the North's nuclear tests and has given support to the UN's sanctions.

South Korea's President Park Geun-hye said the current security situation was "very grave" but that she would "deal strongly" with provocation from the North.

She also said she was ready to talk to Pyongyang if it "comes out on the path toward change".
'Puppet traitors'

The North Korean announcement, carried on the KCNA state news agency, said the North was cancelling all non-aggression pacts with the South and closing the main Panmunjom border crossing inside the Demilitarized Zone.

The threatened pre-emptive nuclear strike seems more bluff than reality, since the North's leaders know it would be suicidal, and an attack on the US seems impracticable given the still technically rudimentary quality of the North's ballistic missile programme and the unproven state of its nuclear miniaturisation technology needed to place a nuclear warhead atop a missile.

A more troubling possibility is that the North might choose - out of irritation with the UN - to precipitate a border clash with South Korea, either on land or sea, as it did before in 2010. Will sanctions persuade or provoke?

The two Koreas have reached a range of agreements over the years, including a 1991 pact on resolving disputes and avoiding military clashes, but the North Korean statement did not expand on what was being cancelled.

It also said it was notifying the South that it was "immediately" cutting off the North-South hotline, saying there was "nothing to talk to the puppet group of traitors about".

The hotline, installed in 1971, is intended as a means of direct communication at a time of high tension, but is also used to co-ordinate the passage of people and goods through the heavily-fortified Demilitarized Zone.

North Korean leader Kim Jong-un also visited front-line military units that were involved in the shelling of a South Korean island in 2010, KCNA reports.

The reports said he had urged soldiers to keep themselves ready to "annihilate the enemy" at any time.

The BBC's Lucy Williamson in Seoul says it appears the North is trying to build a sense of crisis domestically, with a large rally staged in Pyongyang on Friday and reports of camouflage netting on public transport.

North Korea has breached agreements before and withdrawing from them does not necessarily mean war, our correspondent says, but it does signal a more unpredictable and unstable situation.

Shutting down the hotline will leave both more exposed to misunderstandings, she adds.