The exercise, including K-9 self-propelled artillery and multi-rocket launchers, was to show the military's "strong determination" to respond to the DPRK's provocations, the spokesman said.
In Tokyo, Japanese Defense Minister Itsunori Onodera told Reuters that Japan is allowed under the law to carry out strikes against enemy targets "when an intention to attack Japan is evident, the threat is imminent and there are no other options", despite Tokyo having no plan to do so now.
Zhang Xiao'an, vice-president of the United Nations Association of China, warned that some countries may use the nuclear test as an excuse for a new arms race in the region.
"The relevant parties should also give due consideration to regional security concerns," Zhang Xiao'an said.
The Japanese upper house on Friday adopted a resolution strongly denouncing the nuclear test and said Pyongyang should "totally abandon" its nuclear program immediately, Japan's Jiji Press reported.
Seoul may impose new sanctions against the DPRK before Park Geun-hye takes office on Feb 25, the ROK's Yonhap News Agency quoted an unnamed government source as saying on Friday.
The source said the sanctions are independent of those being deliberated at the UN Security Council and could be announced in the coming days "under the incumbent Lee Myung-bak administration".
Scott Snyder, a senior fellow for Korean studies and director of the program on US-Korea policy at the Council on Foreign Relations in the US, believes that sanctions alone will not work with the DPRK, but they may be effective in slowing or delaying its procurement of items from abroad that could be used to advance nuclear and missile programs.
In Beijing, Foreign Minister Yang Jiechi engaged in a series of phone calls with his counterparts after the Foreign Ministry said on Tuesday that China was "strongly dissatisfied with" and "firmly opposed to" the test.
Ted Galen Carpenter, senior fellow for defense and foreign policy studies at the Cato Institute, said: "China and the US need to work together on a new strategy, especially on Washington's part, to bring a nuclear-armed DPRK into cooperative international arrangements."
More than 100,000 troops and civilians on Thursday staged a mass rally in Pyongyang to celebrate the nuclear test, the Korean Central News Agency said.
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