The prospect of a third nuclear test by North Korea has risen as Pyongyang on Wednesday vowed to end denuclearization efforts and strengthen nuclear deterrence in an angry response to stepped-up U.N. sanctions.

Seoul officials believe the North has already completed preparations for another underground test at the Punggye-ri test site in the country’s northeast, where it carried out two nuclear tests in 2006 and 2009.

Another test would make it difficult for the incoming Park Geun-hye government to adopt a reconciliatory policy toward the North despite her election pledge to build trust and seek more dialogue to enhance strained ties, experts said.

They also noted that as the new U.N. Security Council resolution warned of “significant action” against additional provocations, the second-term Barack Obama administration would have difficulty adopting a softer stance in handling a provocative North.

Less than two hours after Resolution 2087 was adopted unanimously on Tuesday to condemn the December rocket launch, the North’s foreign ministry issued a statement saying, “There will be no more discussion over denuclearization of the Korean Peninsula in the future, although there will be talks for securing peace and security on the peninsula.”

It also warned of “physical actions” to strengthen self-defense military capabilities including nuclear deterrence, which reinforced speculation here that the North could launch another nuclear test.

“Pyongyang strongly suggested the possibility of a third nuclear test in the ministry’s statement, but left some room for negotiations given that it did not specifically mention (the test),” said Hong Hyun-ik, research fellow at the think tank Sejong Institute.

Hong stressed the importance of unofficial diplomatic contacts between Washington and Pyongyang, and between the two Koreas, to persuade the communist state, noting the North is well aware of the negative ramifications of another atomic test.

Urging Seoul to engage more actively with the North, he added that after another test, Pyongyang would be emboldened, and might seek to talk only with nuclear powers such as Beijing and Washington while shunning Seoul as a negotiating partner.

“Washington largely sees the North’s nuclear issue in the context of non-proliferation while Seoul focuses on denuclearization. After another test, Seoul’s strategic bargaining position will be undermined,” he said.

Given that its diplomatic decisions have, oftentimes, gone against conventional wisdom, the North could opt for another nuclear test despite the risk of deeper isolation. Amid the growing need for outside assistance to shore up the moribund economy and further strengthen its fledgling leadership, Pyongyang launched two long-range rockets last year.

Observers also argue the North might not fear additional sanctions as it has long survived punitive measures imposed due to its nuclear and missile activities.

“We, outsiders, believe that the North will act rationally and will not take an option that would make it face deeper isolation. But some sorts of (irrational) options including its brinkmanship diplomatic tactics have long been adopted by the North,” said Kim Ho-sup, international politics professor at Chung-Ang University.

“The North may push for the test as it regards the new sanctions as an attack on its sovereign right (to develop a space program), seeks to raise the stakes in future nuclear negotiations with the international community, and could believe it has nothing more to lose given the continuing international sanctions.”

In addition to U.N. sanctions, Seoul and Washington are mulling their own bilateral sanctions to punish the North, which could include reinforced financial sanctions and maritime measures against North Korean vessels suspected of weapons trafficking.

Huh Moon-young, a senior fellow at the state-run Korea Institute for National Unification, pointed out that as the North’s foreign ministry made the official statement, chances of another test are quite high.

“Pyongyang does what its government bodies such as the foreign ministry announce through official channels. But when it wants to reverse it, it should seek justifiable rationales for it. That has been the characteristic of its diplomacy for six decades,” he said.

“With continuing pressure from the outside and amid efforts to consolidate power in the military and other state entities, North Korean leader Kim Jong-un could take a hard-line foreign policy.”

Huh stressed that Seoul, Washington and Beijing need to make efforts to help Pyongyang find an “exit” or rationale to shun any provocative decision and return to the negotiating table to end its nuclear programs.

“If the outside community applies more pressure, Pyongyang may use it to strengthen its internal unity and decide to ‘live by ourselves’ and push for another nuclear test,” Huh said.

“In close consultation among Seoul, Washington and Beijing, they should make efforts to prevent it from taking a confrontational policy course.”

Amid the growing prospect of reconciliation efforts by Seoul and Washington, the ball appears to be in Pyongyang’s court now.

South Korea’s President-elect Park has vowed not to allow the North to be nuclear-armed, but she has pledged to adopt a more flexible, dialogue-based approach under her so-called peninsular trust-building process.

As the new foreign policy and security teams in Washington include top officials such as John Kerry leaning toward more dialogue, hopes have also emerged that the new U.S. administration might pay more heed to mending fences with the North.

By Song Sang-ho (sshluck@heraldcorp.com)