PYONGYANG, North Korea -- Hinting at a missile launch, North Korea delivered a fresh round of war rhetoric Thursday with claims it has "powerful striking means" on standby. Seoul and Washington speculated that it is preparing to test-fire a missile designed to be capable of reaching the U.S. territory of Guam in the Pacific Ocean.

On the streets of Pyongyang, North Koreans shifted into party mode as they 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 his father Kim Jong Il's death.

But while there was calm in Pyongyang, there was condemnation in London, where foreign ministers from the Group of Eight nations slammed North Korea for "aggressive rhetoric" that they warned would only further isolate the impoverished, tightly controlled nation.

North Korea's provocations, including a long-range rocket launch in December and an underground nuclear test in February, "seriously undermine regional stability, jeopardize the prospects for lasting peace on the Korean Peninsula and threaten international peace and security," the ministers said in a statement.

In the capital of neighboring South Korea, the country's point person on relations with the North, Unification Minister Ryoo Kihl-jae, urged Pyongyang to engage in dialogue and reverse its decision to pull workers from a joint industrial park just north of their shared border, a move that has brought factories there to a standstill.

"We strongly urge North Korea not to exacerbate the crisis on the Korean Peninsula," Ryoo said.

U.S. Secretary of State John Kerry was headed to Seoul on Friday for talks with South Korean officials before heading on to China.

"If anyone has real leverage over the North Koreans, it is China," U.S. Director of National Intelligence James Clapper told Congress on Thursday. "And the indications that we have are that China is itself rather frustrated with the behavior and the belligerent rhetoric of ... Kim Jong Un."

In the latest threat from Pyongyang, the Committee for the Peaceful Reunification of the Fatherland, a nonmilitary agency that deals with relations with South Korea, said "striking means" have been "put on standby for a launch and the coordinates of targets put into the warheads." It didn't clarify, but the language suggested a missile.

The statement was the latest in a torrent of warlike threats seen outside Pyongyang as an effort to raise fears and pressure Seoul and Washington into changing their North Korea policies, and to show the North Korean people that their young leader is strong enough to stand up to powerful foes.

Referring to Kim Jong Un, Clapper told Congress that "I don't think ... he has much of an endgame other than to somehow elicit recognition," and to turn the nuclear threat into "negotiation and to accommodation and presumably for aid."

Officials in Seoul and Washington say Pyongyang appears to be preparing to test-fire a medium-range missile designed to be capable of reaching Guam. Foreign experts have dubbed the missile the "Musudan" after the northeastern village where North Korea has a launchpad, saying it has a range of 3,500 kilometres.

Such a launch would violate UN Security Council resolutions prohibiting North Korea from nuclear and ballistic missile activity, and mark a major escalation in Pyongyang's standoff with neighboring nations and the United States. North Korea already has been punished by new UN sanctions for the rocket launch and nuclear test.

Analysts do not believe North Korea will stage an attack similar to the one that started the Korean War in 1950. But there are concerns that the animosity could spark a skirmish that could escalate into a serious conflict.

"North Korea has been, with its bellicose rhetoric, with its actions ... skating very close to a dangerous line," U.S. Defense Secretary Chuck Hagel said in Washington on Wednesday. "Their actions and their words have not helped defuse a combustible situation."

Bracing for a launch that officials said could take place at any time, Seoul deployed three naval destroyers, an early warning surveillance aircraft and a land-based radar system, a Defense Ministry official said in Seoul, speaking on condition of anonymity in line with department rules. Japan deployed PAC-3 missile interceptors around Tokyo.

But officials in Seoul played down security fears, noting that no foreign government has evacuated its citizens from either Korean capital.

"North Korea has continuously issued provocative threats and made efforts to raise tension on the Korean peninsula ... but the current situation is being managed safely and our and foreign governments have been calmly responding," Foreign Ministry spokesman Cho Tai-young told reporters Thursday.

Still, Taiwan urged its citizens Thursday "to suspend travel to South Korea for business, tourism and educational purposes unless it is absolutely necessary."

The Korean War ended in 1953 with a truce, not a peace treaty, and the U.S. and North Korea do not have diplomatic relations.

For weeks, the U.S. and South Korea have staged annual military drills meant to show the allies' military might. North Korea condemns the drills as rehearsal for an invasion.

In retaliation, North Korea for days barred South Koreans from crossing the border to get to factories in Kaesong where they make everything from shoes to suits using North Korean labor. Citing the tensions, North Korea on Monday pulled its more than 50,000 workers from the Kaesong complex, forcing many factories to stop production and jeopardizing the future of the last joint project between the two Koreas.

Discouraged South Korean managers continued leaving Kaesong, packing their cars with goods and belongings.

In Pyongyang, however, there was no sense of turmoil. Across the city, workers were rolling out sod and planting trees in preparation for a series of April holidays.

Students from Kim Chaek University of Science and Technology put on suits and traditional dresses to dance in the plaza next to the Arch of Triumph to mark Kim Jong Un's appointment as first secretary of the Workers' Party a year ago.

Another key appointment falls on Saturday, and flower show and art performances are scheduled in the lead-up to the nation's biggest holiday, the April 15 birthday of North Korea founder Kim Il Sung, father of the country's second leader, Kim Jong Il, and grandfather of the current leader.

No military parade or mass events are expected over the coming week, but North Korea historically uses major holidays to show off its military power, and analysts say Pyongyang could well mark the occasion with a provocative missile launch.

"However tense the situation is, we will mark the Day of the Sun in a significant way," Kim Kwang Chon, a Pyongyang citizen, told The Associated Press, referring to the April 15 birthday. "We will celebrate the Day of the Sun even if war breaks out tomorrow."

During last year's celebrations, North Korea failed in an attempt to send a satellite into space aboard a long-range rocket. The U.S. and its allies criticized the launch as a covert test of ballistic missile technology.

The subsequent launch in December was successful, and that was followed by the country's third underground nuclear test on Feb. 12, possibly taking the regime closer to mastering the technology for mounting an atomic weapon on a long-range missile.