North Korea’s leader Kim Jong-un has expressed his stern determination to take “real, high-intensity, significant” national measures, its state media said Sunday, ratcheting up its nuclear threat.

From hinting at a third nuclear test to stating the U.S. as its military target, Pyongyang has hardened its bellicose rhetoric since Wednesday, when the U.N. Security Council adopted a new resolution to condemn its December rocket launch.

Experts said despite the risk of deeper isolation, the North resorted to brinkmanship again to raise the stakes in future negotiations with Washington, Seoul, and other concerned parties and make the negotiating environment more favorable.

“Regarding the recent grave circumstances surrounding our country (North Korea), a meeting of officials on national security and foreign affairs was held. There, First (National Defense Commission) Chairman Kim Jong-un put forward concrete tasks to each official,” the North’s Korean Central News Agency said.

The state-run agency did not elaborate on the “concrete” tasks, but observers said they might be associated with preparations for a third nuclear test given that Pyongyang has vowed to strengthen “nuclear deterrence.”

Among the participants in the meeting were Choe Ryong-hae, the director of the General Political Bureau; Hyon Yong-chol, chief of the military’s general staff; Kim Won-hong, head of the State Security Department; and First Vice Foreign Minister Kim Kye-gwan.

Since Wednesday, Pyongyang has issued a series of provocative statements hinting at another nuclear test. Seoul believes 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.

Last Wednesday, the North’s foreign ministry warned of “physical action” to strengthen self-defense capabilities including nuclear deterrence. The following day, its powerful NDC said the North’s future rocket and nuclear tests may directly target the U.S.

On Saturday, the Rodong Sinmun, the ruling Workers’ Party’s daily, said, “Based on public demand, Pyongyang does not have any other choice.” It stressed the public called for carrying out what was even stronger than a nuclear test.

Kim Yong-hyun, North Korea expert at Dongguk University, said that the series of statements indicated that Pyongyang was striving to forge a new environment in which they can gain more concessions from the international community.

“Sunday’s KCNA statement appears to include the strongest expression that well explains the characteristics of its brinkmanship diplomacy. Through it, it is saying if the international community moves against its interests, it will push ahead with the nuclear test,” he said.

“But under the current circumstances following the adoption of the new UNSC resolution, it may not be easy for the North to expect the U.S. and South Korea to make any conciliatory move to benefit it in any way.”

Koh Yoo-hwan, another expert at the university, also said that Pyongyang now seeks to up the ante, stressing that Pyongyang is likely to push for another nuclear test.

“The North Korean regime capitalized on the successful launch of the rocket in December to gain public support and strengthen its leadership. But from its perspective, the U.N. sanctions could be perceived as a slap in the face,” he said.

“It is showing that it is pushing for a nuclear test based on the public demand. It could carry out the test, given that not doing it when it has trumpeted the test would make the young leader lose face.”

Meanwhile, the state-run Institute for National Security Strategy predicted that Pyongyang could launch additional provocations in order to “tame” the incoming Park Geun-hye government.

In a report on the review of security conditions in 2012 and prediction of security challenges this year, the institute said that Pyongyang might have a “wait-and-see” stance until Park presents a concrete policy line, and could opt to launch provocations if the policy does not turn out to be favorable for its national interest.

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