North Korea vows to respond to any acts of US aggression

North Korea warned it would respond to "reckless acts of aggression" by America with "whatever methods the US wants to take", after US navy ships were redirected towards its waters.

The country's "self-defensive and pre-emptive strike capabilities with nuclear force at their core" were justified by the current grim situation, officials from Pyongyang said in a statement provided to CNN.

Those remarks come after the US decided at the weekend to redeploy a group of warships, including destroyers armed with the Aegis anti-missile defence system, from Australia to waters offshore the Korean peninsula, following another missile test by the nominally communist regime the week before.

Pyongyang's twice-yearly Supreme People's Congress, which is often accompanied by the test-firing of missiles, is being held on Tuesday.

"We will make the US fully accountable for the catastrophic consequences that may be brought about by its high-handed and outrageous acts," the statement said.

During their meeting in Florida last week, US president Donald Trump and his Chinese counterpart Xi Jinping agreed that a Chinese envoy would travel to South Korea to discuss the situation, amid recent reports that China was also becoming increasingly irritated by the North's constant sabre-rattling.

For its part, on 26 February China stopped all imports of coal from North Korea, its main export product.

China has remained in favour of only using diplomatic persuasion to rein in Pyongyang's ambitions.

To take note of, on Tuesday morning South Korean news agency Chosun indicated China had deployed 150,000 troops to its border with North Korea to guard against a possible influx of refugees should the US launch a preemptive strike.

In remarks to CNN's New Day programme, retired CIA and NSA chief General Michael Hayden said the White House faced a difficult task in trying to do just that.

"No matter what we do, there is this move by North Korea to build missiles and put weapons on top of missiles," Hayden said.

"This is what they count on for regime survival... The best we can do is box it where it is right now," he said.

"I don't think we can make them give up the program."