SEOUL, South Korea (AP) _ North Korea's neighbors issued stern warnings Wednesday against Pyongyang's threat to carry out an unprecedented nuclear test, but the isolated communist country insisted that such a move wouldn't be meant as a provocation.
South Korean officials said there was no sign a test was imminent and warned that such a test could prompt Japan to developing atomic weapons and threaten a regional arms race.
A newspaper in Japan, meanwhile, reported that two Japanese spy satellites had not observed any preparation activities at a suspected underground test site.
China _ the North's main ally and key benefactor _ called on Pyongyang to show calm and restraint, issuing an unusually pointed statement that referred to North Korea by name. The statement contrasted with earlier Chinese responses, which have typically called for restraint from all sides in the dispute.
``We hope the North Korean side will be sure to keep calm and restrained on the nuclear test issue,'' Foreign Ministry spokesman Liu Jianchao said on the ministry Web site.
China, Japan and South Korea also announced a series of summits among their leaders next week, ratcheting up diplomacy over tensions caused by the North's announcement Tuesday that it intends to detonate a bomb.
Such a test would confirm the North's claim that it has atomic weapons, and would severely undermine efforts to prevent an Asian nuclear arms race by getting Pyongyang to disarm.
South Korea's top official on dealings with the North, Unification Minister Lee Jong-seok, said Wednesday that there were no definite signs that the test is imminent.
However, Lee also told lawmakers there was ``a high possibility'' it would eventually take place if ``efforts to resume the six-party talks fail.''
Japan's Asahi newspaper, citing unidentified government sources, reported that two Japanese spy satellites focusing on a suspected underground test site had not observed any activities that could appear connected to test preparations as of Tuesday.
North Korea has boycotted six-nation nuclear talks with China, Japan, Russia, South Korea and the U.S. for nearly a year, angered by American financial restrictions imposed over the North's alleged illegal activities such as money laundering and counterfeiting.
An official at the North's embassy in Australia, Pak Myong-guk, who described himself as a minister, insisted Pyongyang's planned nuclear test ``is not provocative.''
``It is just the corresponding measure for defense, for us to defend ourselves,'' Pak told The Associated Press. ``It is the really essential process for nuclear deterrent.''
The North often insists it needs nuclear weapons to deter a U.S. attack, although this was the first time that Pyongyang had publicly announced its intent to conduct a nuclear test.
South Korea's President Roh Moo-hyun urged a ``cool-headed and stern'' response to the North's announcement. The Foreign Ministry said a nuclear test by North Korea could cause a change in its engagement policy toward the communist regime.
``If North Korea pushes ahead with a nuclear test, North Korea should take full responsibility for all consequences,'' Foreign Ministry spokesman Choo Kyu-ho said after an emergency meeting of South Korean security ministers.
Asked to elaborate on what the consequences would be, Choo said a North Korean nuclear test could bring about a ``shift'' in Seoul's engagement policy toward the North, but stressed that wouldn't mean abandoning that policy altogether.
South Korea has pursued dialogue with North Korea since their leaders first met in a historic summit in 2000. That approach has caused a rift with Washington, which favors a harder line toward the communist regime.
Seoul is one of the main aid providers to the impoverished North, but it suspended regular relief shipments after Pyongyang carried out missile tests on July 5. However, the South later agreed to send emergency aid to help the North cope with the effects of massive floods that struck the country in mid-July.
Despite the nuclear test threat, the South on Wednesday shipped previously promised aid to the North, including 6,400 tons of cement, the Unification Ministry said.
``As North Korea has yet to conduct a nuclear test, it is difficult to immediately halt sending flood relief aid, which is being provided on a humanitarian basis,'' a ministry official said on condition of anonymity, citing official policy.
After the missile launches, the U.N. Security Council unanimously adopted a resolution banning all U.N. members from missile or missile-related dealings with the North.
South Korean Vice Foreign Minister Yu Myung-hwan said the Security Council is expected to take stronger action against Pyongyang if it tests a nuclear weapon.
North Korea ``will face a strong and united response from the international community'' if it conducts a test, Yu told a regular news briefing.
Speaking later to lawmakers, Yu warned a North Korean nuclear test ``could provide a pretext for Japan's nuclear armament. ``
``This will prompt countermoves by China or Russia and lead to a change in the balance of power in the Northeast Asia,'' he said.
U.S. Ambassador John Bolton raised the issue during a regularly scheduled meeting of the U.N. Security Council on Tuesday, and the 15-nation council decided to meet Wednesday morning to address the issue.
Japanese Prime Minister Shinzo Abe said ``we simply could not accept'' a nuclear test by the North.
Abe will head to China on Sunday and to Seoul on Monday, and Roh will travel to Beijing on Oct. 13.
Russia, another key Pyongyang ally, has urged the North to show restraint. Defense Minister Sergei Ivanov also voiced concern Wednesday about the environmental fallout from a possible nuclear test.
In Australia, North Korean Ambassador Chon Jae-hong was summoned to meet senior officials on Wednesday and ``was warned in the strongest possible terms of the severe consequences should North Korea conduct a nuclear test,'' Australian Foreign Minister Alexander Downer said in a statement.
``A nuclear test would be completely unacceptable to the international community, and would provoke a very strong international response,'' Downer said.
The news sent the South Korean stock market tumbling. The market closed down 1.6 percent Wednesday after recovering from deeper lows earlier in the day.
Pyongyang has not conducted any known test to prove its claim that it has nuclear weapons. Some experts believe the North has enough fissile material to build a half-dozen or more nuclear bombs, though there are doubts about whether it could deliver them accurately on a warhead.
Although North Korea is dotted with underground military installations, media reports in South Korea have identified North Hamkyong province on the North's northeast coast as a likely site for a nuclear test.