The North Korean leader Kim Jong-un has visited military units on the frontline of any potential clashes with South Korea and the United States.
It comes as Pyongyang officials threatened to launch a nuclear strike on the US.
Tough new sanctions, imposed by the United Nations, over North Korea's nuclear tests, are aimed at making it more difficult to finance and obtain material for weapons programmes.
The newspaper said officials cancelled a hotline with the US, and the armistice with South Korea which ended the Korean War in 1953.
Threats from North Korea come after UN voted on fresh sanctions. A volatile combination, even if Kim Jong-un's rhetoric is mostly bluster.
Crowds of soldiers run beach to greet North Korean leader Kim Jong-un as he confirms the end of non-aggression pact with the South.