The defiant communist regime in North Korea threatened to conduct two additional nuclear tests plus more missile firings following its underground nuclear test that Pyongyang claims involved a missile warhead-sized weapon.
The underground blast in northeastern North Korea was carried out on the eve of President Barack Obama’s state of the union speech Tuesday night, when the president is expected to announce plans for steeper cuts in United States nuclear forces.
U.S. officials said the test indicates North Korea moved a step closer to having a nuclear warhead small enough to fit on a missile.
Obama called the test a "highly provocative act."
"The danger posed by North Korea's threatening activities warrants further swift and credible action by the international community," Obama said in a statement early Tuesday. "The United States will also continue to take steps necessary to defend ourselves and our allies."
House Armed Services Committee chairman Rep. Howard P. "Buck" McKeon called the North Korean nuclear test "destabilizing" and "unfortunate."
"It is also unfortunate that on the same day the president of the United States plans to announce further reductions in U.S. nuclear weapons, we see another hostile regime unimpressed by his example," McKeon said. "U.S. security cannot, in the face of the president’s sequester and $500 billion in reductions to the DOD budget so far, afford even more cuts to U.S. defense capabilities, such as our nuclear deterrent."
A North Korean Foreign Ministry spokesman issued a statement through state-run media Tuesday asserting the nuclear blast was conducted in as a "countermeasure" to what the spokesman said were U.S. nuclear threats.
"The nuclear test conducted this time is the first round of countermeasures that we have carried out by exercising maximum self-restraint," the statement said. "If the United States makes the situation complicated by remaining hostile through to the end, we will have no choice but to take serial measures with more intense second and third response."
The official Xinhua news agency in Beijing said China’s Foreign Ministry called in North Korea’s envoy there to protest the blast. China reportedly had sought to dissuade North Korea from conducting the test although public statements by Chinese officials leading up to the test did state specifically that Pyongyang should not conduct the test.
The office of director of national intelligence James Clapper issued a statement early Monday describing what it called a "seismic event with explosive characteristics in North Korea." Then early Tuesday the DNI stated that the North Koreans "probably conducted an underground nuclear explosion in the vicinity of Punggye" in Kilju county.
"The explosion yield was approximately several kilotons," the DNI said in a statement. "Analysis of the event continues and we are evaluating all relevant information."
Obama said in his statement, "North Korea’s nuclear weapons and ballistic missile programs constitute a threat to U.S. national security and to international peace and security.
"The United States remains vigilant in the face of North Korean provocations and steadfast in our defense commitments to allies in the region," he said.
The president, however, stopped short of saying whether the United States would increase its missile defense programs or nuclear modernization efforts. He instead stated that the danger from North Korean "threatening" activities "warrants further swift and credible action by the international community."
"The United States will also continue to take steps necessary to defend ourselves and our allies," he said, limiting those efforts to working with allies and partners in the six-nation nuclear talks, the United Nations Security Council, and with U.N. member states.
A KCNA commentary published after the test said it was conducted in response to the "U.S. attitude toward the DPRK's successful launch of satellite Kwangmyongsong 3-2, in particular," that led to a United Nations resolution condemning the launch. DPRK is the acronym for North Korea’s official name, the Democratic People’s Republic of Korea.
"The third underground nuclear test physically demonstrated the high performance of the DPRK's nuclear deterrent which has become smaller, lighter and diversified as it was a primary counter-measure in which it exercised its maximum self-restraint," the commentary said.
"Whether the DPRK will take the second and third tougher measures will entirely depend on the option to be taken by the U.S. in the future," the commentary on KCNA said.
U.S. intelligence analysis of the test indicated that as with the long-range missile test in December, North Korea used deception in the days leading up to the nuclear test. A Feb. 10 report in a North Korean news outlet said the United States and other nations "jumped to conclusions that the republic is planning the third nuclear test, citing their hypothesis and argument." Analysts interpreted the statement as an indicator a nuclear test would not be carried.
Similarly, in the days before the test launch of what the Pentagon called a long-range missile on Dec. 12, North Korean media published false news stories saying the launch was delayed because of technical problems.
South Korea’s National Intelligence Service told Seoul government officials on Tuesday that the North could conduct additional nuclear tests as well as missile firings, news reports from South Korea stated.
"The North may stage other provocations to distract international efforts to impose more sanctions on the North or to push China to eventually side with Pyongyang," NIS director Won Sei-Hoon said, the Yonhap news agency reported.
China’s Foreign Ministry said China "firmly opposes" the latest nuclear test. "On Feb. 12, 2013, the DPRK conducted another nuclear test in disregard of the common opposition of the international community," said the statement, noting that "the Chinese government is firmly opposed to this act."
Shortly before the nuclear test was announced by Pyongyang, a YouTube posting by an official North Korean television channel posted a video clip titled the "Sentiment of the People" that discussed the nation’s nuclear and missile capability and stated that the "shock" of a third nuclear blast could be "enormous."
Several governments denounced the test, including most U.S. allies as well as Russia. The NATO alliance also condemned the test.
Tokyo called the test a grave threat to global and regional peace and said the government would work with the United States, China, Russia, and South Korea to urge Pyongyang to give up its nuclear program.
The latest nuclear test represents a diplomatic failure for the United States, which sought to gain Chinese support for pressure on its fraternal communist ally not to conduct the test.
The State Department privately appealed to China’s government on several occasions in recent weeks to urge North Korea not to conduct the test.
The United Nations is expected to condemn the nuclear test as further destabilizing the region. Additional sanctions on North Korea could be imposed. However, past U.N. sanctions appear to have had a limited effect on the reclusive, impoverished communist state that continues to invest in developing nuclear arms and missile delivery systems.
Obama is expected to announce during his state of the union speech before Congress that the United States will cut its declining nuclear arsenal by an additional one-third.
The United States agreed to reduce its warhead stockpile to 1,550 under the 2010 New START arms treaty. Additionally, 500 warheads could be cut under Obama’s new plan.
Critics of the cuts say the United States is reducing its nuclear arsenal at a time when all other nuclear powers are expanding and modernizing their arsenals.
Obama promised in 2010 that he would spend $85 billion over 10 years to modernize U.S. nuclear weapons but has not pressed Congress to provide the funds. The U.S. nuclear arsenal is aging and in dire need of upgrading both the weapons and the infrastructure required to maintain them.
U.S. officials told the Free Beacon last week that North Korea was preparing to conduct an underground nuclear test coinciding with a political event such as Tuesday night’s state of the union address by Obama.
The officials said North Korea is expected to conduct medium- or long-range missile tests around the time of the nuclear test, including a possible test launch of the new KN-08 road-mobile ICBM.
Testing for a nuclear blast involves seismic monitoring stations as well as special "sniffer" aircraft capable of detecting minute particles sent into the atmosphere in areas around a nuclear test facility.
U.S. officials say a key question is whether the latest test used plutonium to fuel the bomb as occurred in the two previous tests or was a new weapon based on highly enriched uranium.
The nuclear test in 2006 was assessed to have produced a yield of less than 1 kiloton, or 1,000 tons, of TNT. The May 2009 test was assessed as having a yield of about 2 kilotons.