North Korea should be ready to use nuclear weapons “at any time” in the face of a growing threat from its enemies, leader Kim Jong-un has said in a further escalation of tensions on the Korean peninsula.

Kim’s warning, issued through North Korea’s state-controlled media on Friday morning was an attempt to put pressure on the international community after the UN security council on Wednesday developed a list of new sanctions against the regime in response to its recent nuclear test and rocket launch.

Kim, who was supervising the test-firing of newly developed multiple rocket launchers, said North Korea’s situation had become so serious, that it should have the choice of launching a “pre-emptive attack”, a departure from previous claims that the North’s nuclear capability was purely a deterrent.

In an imminent threat to neighbouring South Korea, Kim said the new rocket launchers should be “promptly deployed” along with other new weaponry.

He said the regime’s enemies – notably the US – were threatening North Korea’s survival, the state-controlled KCNA news agency reported.

“At an extreme time when the Americans … are urging war and disaster on other countries and people, the only way to defend our sovereignty and right to live is to bolster our nuclear capability,” KCNA quoted Kim as saying.

“Under the extreme situation that the US imperialist is misusing its military influence and is pressuring other countries and people to start war and catastrophe, the only way for our people to protect sovereignty and rights to live is to strengthen the quality and quantity of nuclear power and realise the balance of power.

“We must always be ready to fire our nuclear warheads at any time.”