(Reuters) - Japan joined the United States on Tuesday in a push for harsher sanctions to punish North Korea after it announced a nuclear test, while Seoul promised to review a "sunshine policy" of engagement with its reclusive neighbor.
But Chinese President Hu Jintao, feted as a friend when he visited North Korea last year, said Beijing still saw room for negotiations to end Pyongyang's nuclear arms ambitions, reports Trend.
Monday's announcement by the communist state that it had detonated a nuclear device underground was a slap in the face for major regional and world powers engaged in six-country talks intended to unravel its nuclear program.
U.S. Democrats, eager to oust Republicans from control of Congress in next month's mid-term elections, wasted no time in accusing President George W. Bush of being in a state of denial about North Korea as he pursued a war in Iraq.
Pyongyang's declaration was also a sharp blow to Hu's doctrine of using economic incentives and diplomatic coaxing to avert the impoverished country's drive to become a nuclear weapons state.
China, in a policy departure, joined the chorus of global condemnation over Pyongyang's claim, branding it a "brazen" act.
In Canberra, Australian Foreign Minister Alexander Downer said North Korea had "humiliated China."
China canceled leave for troops along part of the 1,400-km (870-mile) border with North Korea, a mainland-controlled Hong Kong newspaper reported on Monday.
At the U.N. Security Council, the United States proposed an array of financial and arms sanctions, including inspections of cargo going in and leaving the country. U.N. diplomats said a tough sanctions regime could be in place by the end of this week.
In a draft resolution, U.S. Ambassador John Bolton called for a total arms embargo and a freeze on financial assets relating to Pyongyang's missiles or weapons of mass destruction programs. There was even a proposed ban on luxury goods.
"We're going to take all actions we can, working with our partners, to make it very difficult for North Koreans to get the equipment, get the technology and to get the funding ... to market these weapons around the world," Christopher Hill, the U.S. State Department's point man on North Korea, told CNN.
Japan, which imposed a raft of sanctions following missile test launches by North Korea in July, said it was considering imposing additional measures. However, it wanted confirmation of whether a test actually took place before putting them in place.
"We would like to see proof that such a test took place," Foreign Minister Taro Aso told a news conference, adding that Japan was not yet considering inspections of cargo ships entering or leaving North Korea, a measure proposed by the United States.
A U.S. official said it could take several days for intelligence analysts to determine whether the event near North Korea's border with China was an unsuccessful nuclear test, a small nuclear device or a non-nuclear explosion.
"If it was a nuclear test, it appears to be more of a fizzle than a pop," the official said, calling it "a seismic event ... that would suggest an underground explosion."
Australia's Seismology Research Center put the blast at about one kiloton, the equivalent of 1,000 tons of TNT. The U.S. Air Force dropped a 12.5-kiloton bomb on Japan's Hiroshima in 1945.
Officials in Japan and South Korea said were no reports of changes in radiation levels since Pyongyang's announcement.
In Seoul a spokesman quoted President Roh Moo-hyun as saying that the country's policy of engagement with North Korea -- which has brought a steady stream of cash and aid for Pyongyang's leaders -- would now be reconsidered.
South Korean newspapers slammed Roh on Tuesday for being too soft on North Korea, with one editorial saying the country was in its worst crisis since the Korean War.