Foreign Minister Yun Byung-se expressed concern over possible military conflict in Northeast Asia, noting the ever-increasing tension in the region.
"Conflicts concerning history, territory and maritime security among others are raising concern that a military confrontation owing to miscalculation may become a reality," said Yun at a gathering hosted by the International Peace Institute in New York, Tuesday.
Seoul's top diplomat attributed this to several factors, including Japan's attitude of historical revisionism and North Korea's pursuit of nuclear weapons.
"Misguided nationalism is rearing its ugly head in the form of historical revisionism, or even denialism, thereby prolonging the tension among countries in the region," Yun said.
The historical rift between Japan and its past colonial victims in the region, South Korea and China, still stands strong in Northeast Asia as Tokyo refuses to properly apologize and compensate wartime victims.
"The most urgent task is to prevent the North from conducting another nuclear test and mastering its nuclear weapons delivery capability," said the minister, adding that the provocative nation is currently capable of carrying out a nuclear test at will. "If North Korea were to go ahead with another test in defiance of the collective will of the international community, it will have to pay the heaviest price ever."
Pyongyang has recently been showing signs of setting up a nuclear test.
News broadcaster CNN, quoting a senior U.S. official, reported Monday that a tarp has been set up at the tunnel entrance of North Korea's northeastern nuclear test site of Punggye-ri, indicating that test preparations are in their final stages.
Last month, North Korea threatened to conduct a "new form" of nuclear test.
The Ministry of National Defense recently said that increased activity at the North's underground nuclear test facility had been spotted.
"Faced with such a challenge, my government is making intensive diplomatic efforts to deter North Korea's dangerous provocations," said Yun.
Efforts involve working in concert with countries involved in the six-party talks, members of the U.N. Security Council, the European Union and the Association of Southeast Asian Nations, according to the foreign minister.
The six-nation talks aimed at persuading North Korea to drop its nuclear ambitions have been dormant since late 2008.
The negotiations involve the two Koreas, the United States, China, Russia and Japan.
Yun is currently visiting New York to lead United Nations activities as Seoul holds a one-month presidency of the U.N. Security Council this month.