SEOUL, South Korea -- North Korea said Wednesday that its nuclear weapon program was no longer negotiable, and indicated that it might conduct its third nuclear test to retaliate against the U.N. Security Council's tightening of sanctions against the isolated yet highly militarized country.
Although it was not the first time North Korea has issued such strident rhetoric, its posture -- coming under the new leadership of Kim Jong Un -- threw a direct challenge to President Barack Obama as he starts his second term, and to Park Geun-hye, who will be sworn in as South Korea's president next month.
After years of tensions with North Korea, both Mr. Obama and Ms. Park have recently said they were keeping the door open for dialogue with the North on the premise that such engagement should lead to the eventual dismantling of its nuclear weapons program.
The North's comments came as the United States reaffirmed its policy of punishing North Korea for moving toward development of long-range missiles tipped with a nuclear warhead, spearheading international backing for a unanimous Security Council resolution Tuesday. The resolution condemned North Korea's Dec. 12 rocket launch as a violation of earlier resolutions banning the country from any tests involving ballistic missile technology, and tightened existing sanctions.
In a swift rejection of the U.N. warnings, North Korea said Wednesday that it will take "physical counteraction" to bolster its "nuclear deterrence both qualitatively and quantitatively." It said, "There can be talks for peace and stability of the Korean Peninsula and the region in the future, but no talks for the denuclearization of the peninsula."
By "physical counteraction," analysts in Seoul said, North Korea most likely meant detonating another nuclear device to demonstrate advances in bomb-making. After analyzing debris of the rocket North Korea fired in December to put a satellite into orbit, South Korean officials said the North indigenously built key components of a missile that can fly more than 6,200 miles.
The analysts said the United States would see whether a new nuclear test involved a uranium device, as opposed to the previous two tests that used plutonium bombs. North Korea has recently revved up efforts to enrich uranium, ostensibly as fuel for its new nuclear reactor under construction. But for practical purposes, it could serve as a new and more stable source of fuel for nuclear bombs.
North Korea unveiled a new uranium enrichment plant to a visiting U.S. scholar in 2010. But U.S. and South Korean military intelligence officials, using satellite imagery, have since detected more facilities that they suspected could be part of a more expansive enrichment program, military officials in Seoul said.
In recent months, international experts have detected what appeared to be new tunneling activities and efforts to fix flood damages in the Punggye-ri nuclear test site in northeastern North Korea. Kim Min-seok, spokesman for the South Korean Defense Ministry, told reporters last month that the North could conduct a third nuclear test on short notice once its leadership decided to do so.
North Korea conducted an underground nuclear test in Punggye-ri in 2006 and again in 2009. Each of those tests came as the North was protesting a U.N. decision to expand sanctions as punishment for rocket tests.
Washington and its allies "know better than any others about the fact that ballistic missile technology is the only means for launching satellites, and they launch satellites more than any others," the North Korean statement said Wednesday. "This is self-deception and the height of double-standards. The essence of the matter is the U.S. brigandish logic that a satellite launch for peaceful purposes by a country which the U.S. antagonizes should not be allowed, because any carrier rocket launched by it can be converted into long-range ballistic missile threatening the U.S."
In recent years, North Korea has made it increasingly clear that it is determined to keep its nuclear weapons at whatever cost, undermining a once-popular belief that the Pyongyang government's brinkmanship was a mere bargaining ploy designed to get as many concessions as possible in exchange for nuclear weapons.
Blaming Washington's "hostile policy," the North said Wednesday that it "drew a final conclusion that denuclearization of the Korean Peninsula is impossible unless the denuclearization of the world is realized." The 2005 deal in which North Korea and the United States agreed in principle to dismantling the North's nuclear arms program in return for diplomatic incentives "has now become defunct," it said.world