North Korea leader Kim Jong Un presides over a meeting of the Central Military Commission of the Workers' Party of Korea in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang March 17, 2014. 
 
 SEOUL (Reuters) - North Korea threatened on Sunday to conduct what it called "a new form of nuclear test", raising the level of rhetoric after members of the United Nations Security Council condemned the North's recent ballistic missile launch. 
 
 "It is absolutely intolerable that the U.N. Security Council, turning a blind eye to the U.S. madcap nuclear war exercises, 'denounced' the Korean People's Army (KPA)'s self-defensive rocket launching drills and called them a 'violation of resolutions' and a 'threat to international peace and security' and is set to take an 'appropriate step'," the North's foreign ministry said in a statement on the official KCNA news agency. 
 
 The statement said KPA drills to counter the U.S. will involve "more diversified nuclear deterrence" that will be used for hitting medium- and long-range targets "with a variety of striking power". 
 
 "We would not rule out a new form of nuclear test for bolstering up our nuclear deterrence," the North's statement said, without giving any indication of what that might entail. 
 
 After Pyongyang fired two medium-range Rodong ballistic missiles into the sea off the east coast of the Korean peninsula on Wednesday, the 15-member Security Council on Thursday condemned the launches violating U.N. resolutions. 
 
 North Korea's first firing in four years of mid-range missiles that can reach Japan followed a series of short-range rocket launches over the past two months. 
 
 In defiance of U.N. resolutions, North Korea conducted its third nuclear test in February 2013 and declared it had made progress in securing a functioning atomic arsenal. 
 
 It is widely believed the North does not have the capacity to deliver a nuclear strike on the mainland United States. 
 
 (Reporting by Narae Kim; Editing by Richard Borsuk) ||||| South Korea's new president will not tolerate North Korean provocations but will continue to push for dialogue with Pyongyang, a special envoy to President-elect Park Geun-hye said just hours after the North's top governing body declared it would continue atomic tests and rocket launches. 
 
 In this Jan. 24, 2013 photo, students walk toward Pothong River in Pothong District, Pyongyang, North Korea with the Ryugyong Hotel seen in the background, second right. The banner calls on the people... (Associated Press) 
 
 FILE - In this Dec. 12, 2012 file image made from video, North Korea's Unha-3 rocket lifts off from the Sohae launching station in Tongchang-ri, North Korea. North Korea's top governing body warned Thursday,... (Associated Press) 
 
 FILE - In this Dec. 21, 2012 file image made from video, North Korean leader Kim Jong Un speaks at a banquet for rocket scientists in Pyongyang, North Korea. North Korea's top governing body warned Thursday,... (Associated Press) 
 
 Park is strongly urging North Korea to refrain from conducting a nuclear test that could only worsen the tensions on the Korean Peninsula in the wake of a provocative long-range rocket launch in December, envoy Rhee In-je told The Associated Press and selected news outlets in Davos, Switzerland. 
 
 "President-elect Park makes it clear that North Korea's nuclear ambitions and further provocations against the South will not be tolerated," Rhee said on the sidelines of the World Economic Forum on Thursday. "In particular, she strongly urges North Korea to refrain from further worsening the situation by conducting a third nuclear test." 
 
 But Park, who takes office next month, wants to leave the window open to constructive dialogue with Pyongyang and will continue to provide food and medical aid as part of a "trust-building" policy for the two Koreas. "It is a gradual process based on mutual trust and respect, which can begin with keeping promises," he said. 
 
 She also advocates returning to the six-nation disarmament negotiations, Rhee said. North Korea walked away from those talks in 2009 and has said future disarmament talks are out off the table. 
 
 On Tuesday, the U.N. Security Council voted unanimously to condemn North Korea's Dec. 12 rocket launch as a violation of a ban against missile activity. The council, including Pyongyang ally China, expanded sanctions against the regime. 
 
 North Korea's National Defense Commission responded Thursday by declaring that the regime is prepared to conduct a nuclear test in defiance of U.N. punishment, and it made clear that its long-range rockets are designed to carry not only satellites but also warheads aimed at striking the United States. 
 
 The commission, North Korea's top governing body led by leader Kim Jong Un, pledged to keep launching satellites and rockets and to conduct a nuclear test as part of a "new phase" of combat with the United States, which it blames for leading the U.N. bid to punish Pyongyang. It said a nuclear test was part of "upcoming" action but did not say exactly when or where it would take place. 
 
 "We do not hide that a variety of satellites and long-range rockets which will be launched by the DPRK one after another and a nuclear test of higher level which will be carried out by it in the upcoming all-out action, a new phase of the anti-U.S. struggle that has lasted century after century, will target against the U.S., the sworn enemy of the Korean people," the commission said, referring to North Korea by its official name, the Democratic People's Republic of Korea. 
 
 U.S. Defense Secretary Leon Panetta said he has seen no outward sign that North Korea will follow through soon on its plan to conduct a test. But that doesn't mean preparations aren't taking place. 
 
 "They have the capability, frankly, to conduct these tests in a way that make it very difficult to determine whether or not they are doing it," Panetta told reporters in Washington. 
 
 North Korea claims the right to build nuclear weapons as a defense against the United States, its Korean War foe. 
 
 Their bitter three-year war ended in a truce, not a peace treaty, in 1953, and left the Korean Peninsula divided by the world's most heavily fortified demilitarized zone. The U.S. leads the U.N. Command that governs the truce and stations more than 28,000 troops in ally South Korea, a presence that North Korea cites as a key reason for its drive to build nuclear weapons. 
 
 North Korea is estimated to have stored up enough weaponized plutonium for four to eight bombs, according to scientist Siegfried Hecker, who visited the North's Nyongbyon nuclear complex in 2010. 
 
 In October, an unidentified spokesman at the National Defense Commission claimed that the U.S. mainland was within missile range. And at a military parade last April, North Korea showed off what appeared to be an intercontinental ballistic missile. 
 
 In 2009, Pyongyang declared that it would begin enriching uranium, which would give North Korea a second way to make atomic weapons. 
 
 The National Defense Commission's allusion to a "higher level" nuclear test most likely refers to a device made from highly enriched uranium, said Cheong Seong-chang, an analyst at the private Sejong Institute in South Korea. Experts say North Korea must keep testing its atomic devices so it can make them small enough to mount as nuclear warheads onto long-range missiles. 
 
 North Korea tested atomic devices in 2006 and 2009 after receiving U.N. condemnation for launching long-range rockets. 
 
 The U.S. envoy on North Korean issues, Glyn Davies, urged Pyongyang not to explode an atomic device. 
 
 "Whether North Korea tests or not, it's up to North Korea. We hope they don't do it. We call on them not to do it," he told reporters in Seoul after meeting Thursday with South Korean officials. "It will be a mistake and a missed opportunity if they were to do it." 
 
 White House spokesman Jay Carney on Thursday said North Korea's aggressive stance is unnecessary and warned against any further testing. 
 
 "North Korea's statement is needlessly provocative and a test would be a significant violation of United Nations Security Council resolutions," he said. "Further provocation would only increase Pyongyang's isolation, and its continued focus on its nuclear and missile program is doing nothing to help the North Korean people." 
 
 He said the recent U.N. resolution is a "strong message of the international community's opposition to North Korean provocations and these tightened sanctions will impede the growth of weapons of mass destruction programs in North Korea and the United States will be taking additional steps in that regard." 
 
 Carney did not elaborate on what those steps might be. 
 
 In Beijing, chief North Korea ally China urged restraint, but declined to directly criticize the North's actions. 
 
 "To maintain peninsular peace and stability and achieve denuclearization is conducive to the interests of all sides." Foreign Ministry spokesman Hong Lei told reporters Thursday. 
 
 "The situation now is sensitive and complicated. We hope all sides can stay calm, be careful what they say and do, and avoid escalating tensions," Hong said. 
 
 ___ 
 
 Associated Press writers Jean H. Lee in Seoul, Matthew Pennington in Washington and Christopher Bodeen in Beijing contributed to this report. Follow AP's Korea bureau chief at http://www.twitter.com/newsjean. ||||| Image caption North Korea has issued many threats against the US and Seoul in recent weeks 
 
 North Korea says it has put missile units on stand-by to attack US targets in response to US stealth bomber flights over the Korean peninsula. 
 
 State news agency KCNA said leader Kim Jong-un signed off on the order at a late-night meeting of top generals. 
 
 The time had come to "settle accounts" with the US, KCNA quoted him as saying, with the B-2 flights an "ultimatum". 
 
 Pyongyang has been angered by fresh UN sanctions and annual US-South Korea military drills. 
 
 Russia said it was concerned by "unilateral action being taken around North Korea" and warned against the situation slipping out of control. 
 
 China, North Korea's biggest trading partner, has called on all sides to ease tensions. 
 
 Kim Jong-un "finally signed the plan on technical preparations of strategic rockets of the KPA, ordering them to be stand-by for fire so that they may strike any time", the KCNA report said. 
 
 Analysis At present, the risk is not one of large-scale war or nuclear attack, but one of miscalculation. North Korea continues to search for new ways to issue threats - partly in an attempt by the regime to consolidate power at home, and partly in the hope that the US cancels its exercises as President Clinton did. As Pyongyang does so, the West calls their bluff and continues to carry out drills and B-52 flights over the peninsula. This concerning pattern occurs in the absence of any regular engagement between the US and North Korea. Should it persist, the risk of miscalculation by either side will rise. Viewpoint: What is driving North Korea's threats? 
 
 "If they make a reckless provocation with huge strategic forces, the Korean People's Army (KPA) should mercilessly strike the US mainland, their stronghold, their military bases in the operational theatres in the Pacific, including Hawaii and Guam, and those in South Korea," the agency quoted him as saying. 
 
 Thousands of North Koreans later took part in a march in Pyongyang in support of Kim Jong-un's announcement, the Associated Press news agency reported. 
 
 A Yonhap news agency report citing an unidentified military official said increased activity had been noted at North Korea's missile sites, but this remains unconfirmed. 
 
 The US - which flew two stealth bombers over the peninsula on Thursday as part of the ongoing military drills - has said it is ready for "any eventuality" on the peninsula. 
 
 In a statement, it said that the B-2 planes demonstrated America's ability to "provide extended deterrence" to its allies and conduct "long-range, precision strikes quickly and at will". 
 
 "The North Koreans have to understand that what they're doing is very dangerous," US Defence Secretary Chuck Hagel told reporters on Thursday. "We must make clear that these provocations by the North are taken by us very seriously and we'll respond to that." 
 
 The US flew nuclear-capable B-52 bombers over South Korea earlier this month, in what it called a response to escalating North Korean threats. 
 
 Timeline: Korean tensions 12 Dec: North Korea fires three-stage rocket, in move condemned by UN as banned test of long-range missile technology 
 
 North Korea fires three-stage rocket, in move condemned by UN as banned test of long-range missile technology 12 Feb: North Korea conducts an underground nuclear test, its third after tests in 2006 and 2009 
 
 North Korea conducts an underground nuclear test, its third after tests in 2006 and 2009 7 Mar: UN approves fresh sanctions on Pyongyang; North Korea says it has the right to a "pre-emptive nuclear strike" on the US 
 
 UN approves fresh sanctions on Pyongyang; North Korea says it has the right to a "pre-emptive nuclear strike" on the US 11 Mar : US-South Korea annual joint military drills begin; North Korea says it has scrapped the Korean War armistice (the UN says the pact cannot be unilaterally scrapped) 
 
 : US-South Korea annual joint military drills begin; North Korea says it has scrapped the Korean War armistice (the UN says the pact cannot be unilaterally scrapped) 19 Mar: US flies B-52 nuclear-capable bombers over Korean peninsula, following several North Korean threats to attack US and South Korean targets 
 
 US flies B-52 nuclear-capable bombers over Korean peninsula, following several North Korean threats to attack US and South Korean targets 20 Mar: Broadcasters and banks in South Korea hit by cyber attack, the origin of which remains unknown, days after North Korea says some of its sites were hacked 
 
 Broadcasters and banks in South Korea hit by cyber attack, the origin of which remains unknown, days after North Korea says some of its sites were hacked 27 Mar: North Korea cuts military hotline with South, the last official direct link between the two 
 
 North Korea cuts military hotline with South, the last official direct link between the two 28 Mar: US flies stealth bombers over Korean peninsula; showcasing ability for precision strike "at will" 
 
 In Beijing, Chinese Foreign Ministry spokesman Hong Lei reiterated a call for calm on all sides. 
 
 He told a daily news briefing that "joint efforts" should be made to turn around a "tense situation". He made similar remarks on Tuesday. 
 
 Russian Foreign Minister Sergei Lavrov condemned Pyongyang's actions as "unacceptable", Interfax news agency said. 
 
 He later told reporters that Moscow was concerned that "alongside an adequate reaction from the [UN] Security Council... there are unilateral steps being taken around North Korea". 
 
 "We may simply let the situation slip out of our control and it will slide into a vicious spiral." 
 
 Unprecedented rhetoric 
 
 Tensions in the Korean peninsula are high following North Korea's third nuclear test on 12 February, which led to the imposition of a fresh raft of sanctions. 
 
 North Korea has made multiple threats against both the US and South Korea in recent weeks, including warning of a "pre-emptive nuclear strike" on the US and the scrapping of the Korean War armistice. 
 
 North Korea is not thought to have the technology to strike the US mainland with either a nuclear weapon or a ballistic missile, but it is capable of targeting some US military bases in Asia with its mid-range missiles. 
 
 While North Korea has issued many threats against the US and South Korea in the past, this level of sustained rhetoric is rare, observers say. 
 
 On 16 March, North Korea warned of attacks against South Korea's border islands, and advised residents to leave the islands. In 2010 it shelled South Korea's Yeonpyeong island, causing four deaths. 
 
 When you look at occasions where something really did happen, such as the artillery attack on a South Korean island in 2010, you see there were very clear warnings Professor John Delury, Yonsei university How potent are North Korea's threats? 
 
 On Wednesday, Pyongyang also cut a military hotline with the South - the last direct official link between the two nations. 
 
 A Red Cross hotline and another line used to communicate with the UN Command at Panmunjom have already been cut, although an inter-Korean air-traffic hotline still exists. 
 
 The jointly-run Kaesong industrial park is still in operation, however, and over 160 South Korean commuters entered North Korea yesterday to work in its factories. 
 
 The complex employs an estimated 50,000 North Korean workers and is a source of badly-needed hard currency for the North.
– Having tried out mid-range ballistic missiles in recent weeks, North Korea said today it may conduct a "new form" of nuclear test, the New York Times reports. Pyongyang officials didn't clarify, but the US and its allies have long thought North Korea wants to build small, sophisticated nuclear devices that can ride piggyback on its new missiles. A spokesman for South Korea's foreign ministry said North Korea "will have to pay a price" if it ignores international concerns and carries out the test. For its part, North Korea accused the UN of "turning a blind eye" to "US madcap nuclear war exercises" while denouncing North Korea's, Reuters reports. North Korea also said it wants the ability to hit medium- and long-range targets "with a variety of striking power." Tensions between North and South Korea eased last month, when elderly people separated by the Korean War were allowed short reunions, but the North has since returned to harsh rhetoric—and a paper by a nuclear expert cited the "disquieting possibility" that North Korea is building a network of tunnels to carry out regular nuclear tests with highly enriched uranium.