SEOUL, Feb. 12 (Yonhap) -- North Korea's nuclear test on Tuesday aims to solidify its fledgling leader Kim Jong-un's grip on power and press the international community to respond to its demand for regime guarantee, experts said.
Pyongyang announced that it "successfully" conducted a third underground nuclear test at the northern nuclear site. South Korea also confirmed the nuclear test, citing a magnitude 4.9 tremor detected shortly after noon at the North's Punggye-ri nuclear test complex.
The North had threatened to detonate a nuclear bomb in response to United Nations Security Council's Resolution 2087 in January that condemned the North's Dec. 12 long-range rocket launch. The North previously detonated atomic devices in 2006 and 2009.
"The tremor detected today is much stronger than those detected during the previous tests," said Chang Yong-seok, senior researcher at the Institute for Peace and Unification Studies at Seoul National University.
According to Seoul's Korea Meteorological Administration, magnitudes 3.58 and 4.52 were detected during the nuclear tests in 2006 and 2009, respectively.
"Its explosive force grows some 20 to 30 times larger compared to its first test. We need to check more details, but it is safe to say that North Korea now has greatly enhanced its nuclear capabilities," he added.
The communist country's display of such power initially aims to force the U.S. to the negotiation table where the North expects for Washington and the international community to cave to its demands, according to experts.
"North Korea may eye the previous cycle that its provocation was soon followed by the resumption of bilateral talks with the U.S.," said Kim Kap-sik, a researcher at the National Assembly Research Service.
Following the 2006 test, then U.S. top nuclear envoy Christopher Hill met with his North Korean counterpart Kim Kye-gwan in Beijing and agreed to resume the six-party talks over Pyongyang's nuclear program, while in response to the 2009 nuclear test then U.S. envoy Stephen Bosworth visited North Korea.
"We need to look at the fact that the nuclear test came right before U.S. President Barack Obama's State of the Union address," said Kim Yong-hyun, professor at Seoul's Dongguk University.
"By drawing the attention from the U.S. as well as South Korea and other key players by using the brinkmanship tactics, North Korea will aim to take the upper hand over the international community and repeat its demand of earning the status as a nuclear power," he added.
Seeking the international recognition as a nuclear power, North Korea has called for "nuclear arms control" negotiations with the U.S., not denuclearization talks.
Pyongyang's push for the provocative move despite China's effort to deter it also reflects the North's intention to stress "equal and independent bilateral relations," researcher Chang said. China has long been North Korea's only and closest ally.
South Korean Defense Minister Kim Kwan-jin (R) meets U.S. Ambassador to Seoul Sung Kim (C) and U.S. Forces Korea Commander Gen. James Thurman at the defense ministry in Seoul on Feb. 12, 2013, to discuss steps to counter North Korea's nuclear test. Earlier in the day, North Korea conducted its third nuclear test in its northeastern county of Kilju, following its first test in 2006 and second in 2009. (Yonhap)
Tuesday's detonation can also be seen as Pyongyang's move aimed at addressing its domestic politics.
"North Korea has vowed to achieve the so-called prosperous and powerful nation with strong military and economic clout by 2013. So the leadership would be in need to do something to appeal to its own people," said Cho Dong-jun, professor at the Seoul National University.
"The nuclear test following the successful rocket launch will be a chance for the people there to quell uncertainty about its leadership led by Kim Jong-un, through which Kim will solidify its status and secure legitimacy of the hereditary ruling," said Lee Woo-young, professor at the University of North Korean Studies in Seoul.
Kim Jong-un took the helm of the communist country in December 2011 upon his father Kim Jong-il's death.
North Korean leader Kim Jong-un. (Yonhap file photo)