PYONGYANG has kept the world on edge over an expected missile launch while turning its own energies to celebrating leaders past and present amid soaring tensions on the Korean peninsula.

The United States warned North Korea it was skating a "dangerous line", as South Korea remained on heightened alert for any missile test that could start a whole new cycle of tensions in a region already on a hair-trigger.

G8 foreign ministers meeting in London drove home the message, condemning "in the strongest possible terms" the North's nuclear activities and threats to the region.

CLICK HERE FOR CONTINUING LIVE COVERAGE OF THE NORTH KOREA CRISIS.



The following is our earlier rolling coverage of what happened overnight.

6:10am (AEST): President Barack Obama says now is the time for North Korea to end its belligerence. He says the United States will take, in his words, "all necessary steps" to protect its people.

But Mr Obama also says that no one wants to see a conflict on the Korean Peninsula.

North Korea ratcheted up its threats against the US after the UN Security Council levied new economic sanctions on the isolated nation. The penalties were in response to a February rocket launch.

Mr Obama spoke alongside UN Secretary-General Ban Ki-moon after the two met in the Oval Office.

5:15am (AEST): North Korea is poised to launch as many as five missiles from its east coast, South Korean intelligence officials said.

media_camera North Korea's missiles

"There are signs the North could fire off Musudan missiles any time soon," an unidentified intelligence source in Seoul told the state-run Yonhap news agency.

Others think the military exercise is just part of the festivities planned for a national holiday on Monday marking the birthday of the country's late founder, Kim Il Sung.

"There is no threat,” said Xu Guangyu, a senior military analyst in Beijing. “The grandson is using the missiles to salute his grandfather and celebrate his power.’’

4:20am (AEST): China appears "frustrated" with volatile rhetoric from its North Korean allies but is eager to see the regime stay in power as a "buffer state" on its border, US spy chief James Clapper said Thursday.

The national intelligence director told lawmakers North Korea's young leader Kim Jong-Un, who has threatened nuclear war with the United States, was testing China's patience.

"China is under new leadership and the indication we have is that China is rather frustrated with the behaviour and belligerent rhetoric of Kim Jong-Un," Mr Clapper told the House Intelligence Committee.

3:30am (AEST): The Washington Post says that Google searches for North Korea in the US are seven times higher than the last peak, which was during the country's 2006 nuclear test. More Americans are Googling North Korea than Beyonce or Barack Obama, two of the most consistently popular searches.

Pew estimates that 36 per cent of Americans are following the news “very closely”, which is unusual for an international news story. About 56 per cent said the US should take the threats “very seriously.”

However, despite Americans reading more about North Korea, Pew found 47 per cent believe the country has a nuclear missile that could hit the US (which it does not).

media_camera North Korean military officers on a boat on the Yalu River, the China-North Korea border river, near North Korea's town of Sinuiju.

3:13am (AEST): UK foreign secretary William Hague says the G8 (US, Britain, France, Germany, Italy, Japan, Canada and Russia) would not be intimidated by North Korea.

"If there is a missile test, we will advocate further measures to the UN security council," he said.

media_camera British Foreign Secretary William Hague holds a news conference after hosting the G8 Foreign Ministers meeting in Lancaster House in London.

2:48am (AEST): CNN's Australian reporter Anna Coren says it is "business as usual" in South Korea as it faces the prospect of war with North Korea.

Coren said South Koreans seem more interested in the imminent release of pop artist Psy's new song Gentleman than they are about the prospect of war.

1.54am (AEST): One of China's leading experts on North Korea has warned there is an 80 per cent chance of war breaking out on the Korean Peninsula.

"There is a 70 to 80 per cent chance that a war will happen because North Korean leader Kim Jong-un may want to use this opportunity to force a reunification of the Korean Peninsula," Zhang Liangui, a professor of international strategic research at the Communist Party's Central Party School, told the South China Morning Post.

Professor Zhang said China needed to do more to get nuclear weapons out of North Korean hands.

media_camera South Korean Air Force's E-737 Peace Eye, airborne early warning and control (AEW&C) aircraft. South Korean and US forces raised their alert status to "vital threat" before an expected North Korean missile test.

"The longer we delay fixing it, the more difficult the situation will become," he said. "China needs to seriously consider how to tackle the problem."

media_camera A North Korean soldier, background, looks to the southern side as South Korean soldiers stand guard at the border village of Panmunjom, which has separated the two Koreas since the Korean War, in Paju, north of Seoul. Picture: Lee Jin-man

1.11am (AEST): Top US intelligence officials say North Korea's new leader is trying to show the world and his people that he is in charge, rather than trying to trigger military conflict.

Director of National Intelligence James Clapper told Congress that his analysts believe North Korean leader Kim Jong-un is using rhetoric to gain recognition, and to manoeuvre the international community into concessions in future negotiations.

CIA director John Brennan says judging his actions is made tougher because he hasn't been in power long.

Mr Clapper says the intelligence community believes the North would only use nuclear weapons to preserve the Kim regime, but says they do not know how the Kim regime defines that.

Both men say China is best able to influence North Korea to tone down its rhetoric.

12.50am (AEST): Former US Vice President Dick Cheney has given his fellow Republicans a dire warning on the ongoing crisis in North Korea.



“We’re in deep doo doo,” Mr Cheney told Republican lawmakers, according to a leadership aide who spoke to CNN.

media_camera A North Korean Air Koryo attendant wears a pin showing portraits of the late North Korean leaders Kim Il Sung and Kim Jong Il, while she prepares the cabin before take off for Pyongyang from Beijing. Picture: Alexander F. Yuan

media_camera South Korean soldiers sit in a truck at the inter-Korean transit office in Paju, South Korea.

12.22am (AEST): Bloomberg News provides some analysis of North Korea's propaganda machine which has described Hillary Clinton as "funny lady" who is “by no means intelligent” and describes the continental US as being “similar to a boiled pumpkin”.

11.40pm (AEST): Why does North Korea get so upset when the US and South Korea hold joint war games? Find out why here.

11.26pm (AEST): On the streets of Pyongyang, North Koreans have celebrated the anniversary of leader Kim Jong-un's appointment to the country's top party post - one in a slew of titles collected a year ago in the months after father Kim Jong Il's death.

North Korean students put on suits and traditional dresses to celebrate Kim Jong-un's appointment as first secretary of the Workers' Party a year ago.

A flower show and art performances are scheduled over the next few days in the lead-up to the nations' biggest holiday, the April 15 birthday of North Korea founder Kim Il Sung.

media_camera North Koreans dance together beneath a mosaic painting of the late leader Kim Il Sung during a mass folk dancing gathering in Pyongyang to mark the anniversary of the first of many titles of power given to leader Kim Jong-un after the death of his father Kim Jong Il. Picture: David Guttenfelder

10.30pm (AEST): North Korea delivered a fresh round of rhetoric on Thursday with claims it had ''powerful striking means'' on standby for a launch, Fox News reports.

10.10pm (AEST): Reports that North Korea is ready to file a nuclear missile come after the rogue nation was said to be 'shuffling' its mobile missile launchers after Japan reported spotting one in a "ready to fire" position.

9.50pm (AEST): US Secretary of State John Kerry (centre) has been pictured taking a walk in Green Park during a break in the G8 Foreign Ministers meeting in central London on Thursday.

G8 Foreign Ministers are holding a two-day meeting, with the situation between North and South Korea topping their agenda on day one.

media_camera US Secretary of State John Kerry (centre) takes a walk in Green Park during a break in the G8 Foreign Ministers meeting in central London on Thursday.

7.50pm (AEST): North Korea dominates G8 talks

G8 foreign ministers including US Secretary of State John Kerry have held a second day of talks in London with the crisis on the Korean peninsula topping the agenda.

Kerry has already met with his Russian and Japanese counterparts to discuss the Korean crisis, in which US Defence Secretary Chuck Hagel warned Pyongyang was ''skating very close to a dangerous line''.

The secretive communist state has threatened nuclear strikes against the United States and South Korea, and observers are expecting a missile launch at any time.

Foreign Minister Sergei Lavrov of Russia, which maintains close ties to North Korea's key ally China, warned after talks with Kerry on Wednesday against exacerbating tensions with military manoeuvres.

While stressing that Russia and the United States had ''no differences'' on North Korea, Lavrov said: ''One just shouldn't scare anyone with military manoeuvres and there's a chance that everything will calm down.''

Kerry also held talks late Wednesday with Japanese Foreign Minister Fumio Kishida, where they discussed China's role and how to ''change the dynamic'' in North Korea, according to a US State Department official.

media_camera A South Korean protester attaches a picture of North Korean leader Kim Jong Un with balloons on a barricade during a rally demanding a regular operations of the Kaesong industrial complex near Unification Bridge near the border village of Panmunjom in Paju, north of Seoul, South Kore.

The US secretary of state, who will visit South Korea on Friday, ''emphasised the importance of continuing to put pressure on North Korea with economic sanctions,'' the official said.

The Group of Eight rich nations are Britain, Canada, France, Germany, Italy, Japan, Russia and the United States.

Britain, which holds the rotating chairmanship of the group this year, will host a leaders' summit in Northern Ireland in June.

7.12pm (AEST): South Korea urges North to talk on Kaesong

South Korea has called for negotiations with North Korea on the future of the Kaesong joint industrial zone, which Pyongyang has threatened to shut down permanently after suspending operations.

''Normalisation of the Kaesong industrial complex must be solved through dialogue,'' the South's Unification Minister Ryoo Kihl-Jae told reporters.

''I urge North Korea to come to the dialogue table.''

Pyongyang announced the withdrawal of its 53,000 workers and the suspension of operations at Kaesong at the beginning of the week, as military tensions on the Korean peninsula soared.

A rare symbol of cross-border economic cooperation, Kaesong is a crucial hard currency source for the impoverished North, through taxes and revenues, and from its cut of the workers' wages.

media_camera A South Korean soldier sets a barricade on the road leading to North Korea at a military checkpoint in the border city of Paju.

There are 123 South Korean companies operating in Kaesong, which lies 10 kilometres inside North Korea.

South Korea's new President Park Geun-Hye described the suspension of operations as ''very disappointing'' but Pyongyang today said her administration was personally responsible.

''Needless to say Kaesong industrial district will cease to exist should the Park Geun-Hye regime continue pursuing confrontation,'' a spokesman for the North's Bureau for Central Guidance to the Development of the Special Zone said.

''The current powerholder in the South can never be able to shake off responsibility for having Kaesong, which survived even the traitor Lee Myung-Bak's term in office, all but closed.''



7pm (AEST): The foreign editor of The Australian Greg Sheridan joined David Speers on PM Agenda. See what he had to say about North Korea's threats in the video below.

5:01pm (AEST): South Korea denounced a barrage of war-like threats from North Korea as a "useless" tactic, making it clear that Pyongyang will face consequences if it follows through with an expected missile launch, Yonhap News Agency reported.

The South Korean and U.S. militaries remained on high alert with North Korea expected to test-launch at least one mid-range ballistic missile in the coming days.

3:10pm (AEST): Japan's Chief Cabinet Secretary Yoshihide Suga said the government was doing everything it could "to protect the lives and the safety of our people''.

media_camera A Japanese soldier walks past a Patriot Advanced Capability-3 (PAC-3) missile launcher deployed at the Defence Ministry in Tokyo.

"We are aware of all sorts of information. We are sharing information with South Korea and the United States,'' Suga said.

Two PAC 3 Patriot anti-missile batteries now sit on a baseball pitch in the grounds of Japan's Ministry of Defence, pointing northwest in the general direction of North Korea, CNN reported.

They were moved here to the heart of the Japanese capital in the early hours yesterday, alongside further batteries in two Tokyo suburbs.

NORTH KOREAN IN A PERMANENT WAR

2:58 (AEST): US confirm sea-based radar ready for missile launch

A powerful US military sea-based radar is now in place to detect any possible missile launches by North Korea, according to a senior US defence official in Washington.

"The SBX is in position,'' the defence official, who spoke on condition of anonymity, told AFP.

The official would not offer more details but confirmed the SBX, a floating X-band radar that resembles a giant golf ball, had reached a location at sea where it could track missiles fired by the Pyongyang regime.

North Korea has proved quite adept at confounding intelligence monitoring in the past.

media_camera US Army soldiers prepare for an exercise during their annual military drills with South Korea in Yeoncheon, South Korea, near the border with North Korea.

Its long-range rocket launch in December had been widely flagged in advance and was subjected to intense satellite scrutiny. In the end, the rocket blasted off hours after a succession of South Korean media outlets, citing satellite imagery analysis by government, diplomatic and military sources, suggested the launch was facing a lengthy delay.

2:.35 (AEST): Missiles shifted to interfere with monitoring

Several missiles have moved repeatedly on North Korea's east coast in an apparent attempt to interfere with intelligence monitoring by South Korea and the US,

Intelligence analysis, reported by South Korea's Yonhap News Agency, stated that the North has moved two Musudan intermediate missiles, which had been concealed in a shed in the eastern port city of Wonsan.

Four or five wheeled vehicles, suspected to be so-called transporter erector launchers (TEL), were also spotted being moved around in South Hamgyeong Province.

1:03 (AEST): United States island of Guam placed on 'yellow' alert

Guam has raised its official threat level and tested its emergency alert system after warnings from North Korea identifying the island as a potential missile target, according to news agency AFP.

With a North Korean missile test expected at any time, authorities said the US territory in the western Pacific was on yellow alert, the middle phase of a three-step "traffic light" system comprising green, yellow and red levels.

"This is the same colour used by government agencies to indicate there is a medium risk for the island," the government said in a statement.

media_camera A US Air Force F-16 fighter jet prepares to land on the runway during a military exercise at the Osan US Air Base in Osan, South Korea.

"The government will continue to operate like normal, with a few government agencies participating in emergency preparedness and planning."

12:53 (AEST) South Korea 'ready to activate defence missiles'

Seoul has announced it is ready to activate its Patriot PAC2 missile defence system. The statement said the interceptor missiles cannot cover all of South Korea, but will protect everything within its reach.

The missile system is deployed around Seoul, and is believed to have a reach of up to 30km.

1:18 (AEST) Two "Musudan" missiles being moved

Yonhap news agency reports intelligence analysts as saying two Musudan missile launchers have been seen moving in and out of a concealed building in the port city of Wonsan.

Several mult-wheeled vehicles, suspected to be transporter erector-launchers, have also been seen on the move in South Hamgyeong Province.

12:47 (AEST) North Korea shuffles launcher positions

media_camera FILE - This April 5, 2009 file image made from KRT video, shows the launch of a missile in Musudan-ri, North Korea. North Korea fired a long-range rocket Wednesday, Dec. 12, 2012, South Korean officials said, defying warnings from the U.N. and Washington only days ahead of South Korean presidential elections. (AP Photo/KRT TV, File) NORTH KOREA OUT, TV OUT

There are reports that South Korean army officials believe North Korea is in the process of moving its missile launchers on the coast of the Sea of Japan to cause confusion among US, Japanese and South Korean intelligence agencies.

12:41 (AEST): China warns North Korea: Do not misjudge situation

The Chinese People's Daily Online has published an article warning North Korea "not to misjudge" the situation with the United States and South Korea.

Chinese Foreign Minister Wang Yi has reportedly spoken with UN Secretary General Ban Ki-moon over the phone, expressing severe concern over the current tense situation on the Korean Peninsula.

He reportedly said Beijing "does not allow troublemaking at the doorsteps of China."

The article goes on to defend North Korea's right to develop its weaponry, "but there is no reason to violate the relevant resolutions of the United Nations Security Council to engage in nuclear testing and launch missile using ballistic missile technology".

"The DPRK has its own special circumstances, political needs, policy choices and political language style, which is its internal affairs and the outside world has no right to interfere in. But if its choice and words intensifies the Korean Peninsula tensions and affects peace and stability in the region, it becomes the international issues. The situations development on the peninsula will not necessarily go according to the ideas and expectations of the DPRK."

12:37 (AEST): Financial markets show little fear

South Korean news agency Yonhap reports local financial markets appear largely unmoved by the most recent developments in the North Korean missile crisis.

Trade is continuing within "normal boundaries".

12:18 (AEST): Japan says missile may be "Musudan".

A Japanse official has told NBC News that the missile spotted in a firing posture could be the "Musudan" medium range type.

This missile has a potential range of up to 4000km, placing all of Japan and the United States base on the island of Guam within its reach.

It is, however, a relatively new type that has not yet undergone extensive testing.

The official said the discovery may be part of North Korea's "strategy of deception".

12:10 (AEST): South Korea 'concerned' at developments

Senior South Korean defence officials are reportedly saying they expect a launch within the next few hours.

South Korean officials have announced they are very concerned at the recent sighting.

"Nobody knows if North Korea will launch Scud, Rodong or Musudan (missiles), how many... or (what) direction," a statement read.

"We are at full readiness posture worrying that missile(s) North Korea may launch will threaten our citizens and territory."

EARLIER

Kyodo News reports the latest missile launcher sighting comes after Japan moved itself to a heightened state of alert earlier this week, deploying missile to surround the capital Tokyo and key defence facilities.

Defense Minister Itsunori Onodera said that so far Tokyo was responding to the sighting by "gathering a variety of information ... with a sense of tension,'' according to Kyodo.

South Korean and US forces last night raised their alert status to the highest possible level as more missile launchers were spotted on the move.

South Korea's Yonhap news agency quoted a government source saying Pyongyang might be preparing "multiple" launches, after other launch vehicles were reportedly detected carrying shorter-range SCUD and Rodong missiles.

The military alert status is now at "vital threat" level before an expected North Korean missile test as the Pentagon warned a bellicose Pyongyang it was "skating very close to a dangerous line".

The launch is expected to come at any time.

EX-SPY SAYS JONG-UN STRUGGLING TO CONTROL TROOPS.

The South Korea-US Combined Forces Command raised its "Watchcon" status from 3 to 2 to reflect indications of a "vital threat", Yonhap news agency said, citing a senior military official.

Watchcon 4 is in effect during normal peacetime, while Watchcon 3 reflects indications of an important threat. Watchcon 1 is used in wartime.

The North last week told foreign diplomats in Pyongyang they had until April 10 to consider evacuation, fuelling speculation of a launch between April 10 and April 15, during birthday celebrations for late founder Kim Il-Sung.

Any launch could coincide with visits by US Secretary of State John Kerry and NATO chief Anders Fogh Rasmussen, who will both be in Seoul on Friday.

South Korean Foreign Minister Yun Byung-Se told parliament the launch could take place "any time" and warned Pyongyang it risked triggering a fresh round of UN sanctions.

US Defense Secretary Chuck Hagel told reporters on Wednesday that the United States and its allies hoped Pyongyang would tone down its inflammatory language, but said the American military was prepared for any possibility.

"North Korea ... with its bellicose rhetoric, its actions, has been skating very close to a dangerous line," he said.

"Our country is fully prepared to deal with any contingency, any action that North Korea may take or any provocation that they may instigate."

MISSILE THREAT TO AUSTRALIA `REAL'.

THE TWO FACES OF KIM JONG-UN.

GALLERY: KOREAN TENSIONS MOUNT.

Russian Foreign Minister Sergei Lavrov warned against heating up the crisis and stressed Moscow and Washington had a common stance.

"One just shouldn't scare anyone with military manoeuvres and there's a chance that everything will calm down," Lavrov told reporters after meeting Kerry in London.

Kerry also discussed North Korea with Japan Foreign Minister Fumio Kishida in London and emphasised the importance of putting pressure on Pyongyang with economic sanctions, a senior State Department official said.

South Korean intelligence says the North has prepared two mid-range missiles for imminent launch from its east coast, despite warnings from ally China to avoid provocative moves amid soaring tensions.

On Tuesday the North reiterated a warning that the peninsula was headed for "thermo-nuclear" war and advised foreigners to consider leaving South Korea.

Although the North's warnings to embassies in Pyongyang and foreigners in the South were largely shrugged off, there is growing global concern that sky-high tensions might trigger an incident that could swiftly escalate.

The mid-range missiles mobilised by the North are reported to be untested Musudan models with an estimated range of anywhere up to 4000 kilometres.

That would cover any target in South Korea and Japan, and possibly even US military bases on the Pacific island of Guam.

The US military's top officer, General Martin Dempsey, told a press conference that he could not publicly comment on intelligence estimates as to how close North Korea was to placing a nuclear warhead on a missile.

But the chairman of the US Joint Chiefs of Staff said the United States military was ready for the "worst case" scenario.

"They have conducted two nuclear tests. They have conducted several successful missile launches," Dempsey said.

"And in the absence of concrete evidence to the contrary, we have to assume the worst case, and that's why we're postured as we are today," the four-star general added.

The military has deployed US naval ships in the region capable of shooting down incoming missiles and staged a show of force with bomber aircraft in a bid to deter North Korea from launching any attack.

Hagel's comments came amid widespread speculation North Korea is poised for a missile launch in defiance of UN Security Council resolutions.

The head of US Pacific Command, Admiral Samuel Locklear, told senators Tuesday that he favoured shooting down a North Korean missile only if it threatened the United States or Washington's allies in the region.

Locklear, however, said he was confident the US military would be able to detect quickly where any missile was headed.

At budget briefings at the Pentagon on Wednesday, senior officials said automatic cuts adopted by Congress were worrying but would not affect the combat readiness of US troops or air squadrons in or near South Korea.

"I don't want to suggest to the North Koreans they have a free pass here," said comptroller Robert Hale, who oversees Defense Department finances.

"We will protect the readiness of the forces on the Korean peninsula and any that are deployed."

Meanwhile, the US Air Force is taking aim at its big costs of fuel and flight this week, temporarily halting training operations for 12 active duty fighter and bomber squadrons across the United States in order to save nearly $300 million.

New details on the cuts emerged today. They will total 45,000 flight hours, and hit squadrons in eight fighter wings in at least seven states and the Air Warfare Center at Nellis Air Force Base in Nevada.

The cuts will not affect current military operations, such as fighters in Afghanistan or bombers training over South Korea. But the Air Force warned that they will have a ripple effect, sharply reducing the service's ability to be prepared for future operations because pilots must meet minimum flight hour requirements in order to fly.

Originally published as 'An 80 per cent chance of war'