North Korea threatens nuclear strikes on US, South Korea

North Korea, enraged by the fresh UN sanctions and the start of a joint military exercise by arch foes South Korea and the United States, has threatened both Seoul and Washington of a "pre-emptive nuclear strike of justice."

While the threat seems to have been prompted more by the start of huge US-South Korean military drills, the United Nations also recently slapped the North with some of the harsh sanctions, and South Korea has taken a harder than usual line saying it will announce new unilateral sanctions against a collapsed government in Pyongyang.

Pyongyang, which ensnared the whole world with its recent missile and nuclear tests, says the joint drills set to start today and extend up to the end of April, are invasion rehearsals.

North Korea's powerful National Defence Commission threatened strikes against targets in the South, US bases in the Pacific and the US mainland, saying its enemies "are working with bloodshot eyes to infringe upon the dignity, sovereignty and vital rights" of North Korea.

"If we push the buttons to annihilate the enemies even right now, all bases of provocations will be reduced to seas in flames and ashes in a moment," the North's statement said.

The US is mobilising some 17,000 troops for the exercise, the largest number of American forces in about 40 years and about twice the size of a year earlier, while some 300,000 South Korean troops will take part, according to military officials.

The US will also deploy the nuclear-powered aircraft carrier USS John C Stennis (CVN-74), a nuclear-powered submarine, aerial tanker aircraft and reportedly the B-2 stealth bomber during the annual springtime exercises.

While, a pre-emptive military strike by South Korea or the United States on targets inside North Korea is unlikely, North Korean leader Kim Jong has been using threats against South Korea and the United States to boost his authoritarian hold on North Korea ever since he assumed power after his dictator father's death in December 2011.

The rhetorics spike when Washington and Seoul stage annual defensive springtime war games, ostensibly against the bellicose North Korean state.

But such postures cause unease in Seoul and in Washington because North Korea just as its rhetoric is piling up troops and weaponry across the borders with South Korea, and it is an hour's drive from the South Korean capital Seoul and its 10 million residents.

However, the animosity between the two Koreas erupts to bloody border skirmishes and at least 50 South Koreans were killed in attacks in 2010 that Seoul blames on the North.