North Korea is cancelling a non-aggression pact with South Korea and reiterating past threats in anger over a UN Security Council vote to impose more sanctions for its third nuclear test, Belfast Telegraph reported.

The statement the North issued comes after the council levelled tough new sanctions targeting its economy and leadership.

North Korea has already threatened a pre-emptive nuclear strike on the U.S..

North Korea says it will retaliate with "crushing strikes" if enemies intrude into its territory. It also says it is voiding past nuclear disarmament statements between North and South Korea.

It previously said it was cancelling a hotline with the U.S. and the armistice that ended the Korean War in 1953.