In a meeting with ministry officials, Yu Woo-ik claimed the overall situation facing South Korea remains grave and made clear that it is wrong to view the expected atomic detonation in the same light as the tests conducted in 2006 and 2009.
"The first and second tests can be seen as part of Pyongyang's efforts to develop nuclear capability, while a third detonation could mean it is in the final stages (of making weapons)," he claimed.
Pyongyang has repeatedly denounced the U.N Security Council resolution passed last week that condemned its launch of a long-range rocket on Dec. 12, warning it will develop its nuclear deterrence to meet external challenges.
Satellite photo of North Korea's Punggye-ri nuclear test site (Yonhap file photo)
Seoul said that the North has the means to conduct a nuclear test once a decision is made by its leadership. The latest spy satellite photos of the Punggye-ri nuclear test site showed workers had built screens over the entrances of tunnels where nuclear weapons may have been buried in preparation for a test. The screens could be hiding last-minute preparations from satellite observation and are viewed as a tell-tale sign that the test may be imminent.
The minister said that because of the greater threat the next detonation poses to national security, the South should not let its guard down and deal with the move in a firm manner.
"Handling this potential test like it dealt with the two previous detonations is not the right way," he said.
The minister's remarks come as Seoul warned Thursday that if the North conducts another test, it could face an unprecedented level of sanctions that would make the communist country's leadership regret its decision to oppose the international community. Officials at the meeting chaired by President Lee Myung-bak did not elaborate on details of what kinds of sanctions could be imposed, but said the country was in consultations with the United States, China and Japan.
Yu also said there is a need to look for fresh ways to prod the North to make "right choices" on its weapons of mass destruction program.
He said the first steps are for Pyongyang to accept such universal values as human rights and take concrete measures to improve the welfare of its people.
"The country's development of rockets and nuclear weapons is distorting the distribution of limited resources in the country and that is further hurting the daily lives of North Koreans," he said.
Yu called on lawmakers to pass a bill that supports human rights in the North and lays the legal foundation to establish a South-North cooperation fund. The creation of the fund has been stalled in parliament for several years.
He also said that South Koreans must show their joint resolve in the push for unification, which can help advance inter-Korean cooperation.