Asian and European foreign ministers have urged North Korea to rejoin talks on its nuclear programme amid fears it is about to test a nuclear bomb.
There are reports that N Korea may be about to test a nuclear warhead
The ministers expressed "deep concern" about Pyongyang's claim to have developed nuclear weapons.
Their statement, from a summit in Japan, came a day after US intelligence reports that a test was being prepared.
The UN's atomic watchdog has appealed to world leaders to do their utmost to prevent such a test from happening.
A joint statement issued at the 38-nation Asia-Europe Meeting (ASEM), called on Pyongyang to rejoin talks on its nuclear programme.
"The ministers strongly urged the DPRK [North Korea] to return to the negotiating table of the six-party talks without any further delay and to make a strategic decision so as to achieve the denuclearisation of the peninsula in a peaceful manner through dialogue," it said.
Pyongyang has shunned the multilateral discussion of its nuclear activities for almost a year.
Mohamed ElBaradei, the head of the UN's atomic watchdog, has warned a test would have "disastrous political and environmental consequences".
Satellite images inconclusive
Recent images taken by US spy satellites reportedly show activity at a suspected North Korean test site at Gilju, in the north-east of the country.
The images show excavation and some construction which, a US defence official told the BBC, could be preparations for an underground nuclear test.
But the official also warned that the US intelligence community had not concluded that a nuclear test was imminent.
Instead, the official said, it could simply be a ruse by North Korea to strengthen its bargaining power with Washington.
The BBC's Jonathan Head in Kyoto says China's Foreign Minister Li Zhaoxing is likely to come under pressure to show more willingness to try to bring North Korea back to the talks.
But he says there is disagreement on how to persuade Pyongyang to return to the six-party negotiations, involving the two Koreas, Russia, China, the US and Japan.
Japan, he says, supports the threat of UN Security Council sanctions whereas China and South Korea believe this approach to be too provocative.
Complicating these differences, our correspondent adds, is the mistrust and rivalry which surfaced recently between Japan and China which is preventing Asia's most powerful countries from presenting a united front against North Korea.