"I think a very negative reaction would follow another test and that tougher measures would probably be taken," he said.

Analysts said Losyukov's statement marked a hardening of the Russian position on North Korea ahead of February 8 talks in Beijing -- involving China, Japan, South and North Korea, Russia and the United States -- to try to persuade Pyongyang to give up its military nuclear programme.

According to Losyukov, "concrete" results are unlikely in Beijing, but "it could be possible to lay out quite precisely the route toward achieving them."

Reflecting the growing flurry of diplomatic activity ahead of next week's negotiations, Russian Foreign Minister Sergei Lavrov talked by telephone with his South Korean counterpart Song Min-Soon to discuss "resolving the nuclear problem on the Korean peninsula," Interfax reported.

South Korea's negotiator to the six-nation talks, Deputy Minister Chun Young-Woo, was due to meet with Losyukov in Moscow on Thursday to discuss a "road map" plan on the issue.

The last round of talks in China in December ended in deadlock after Pyongyang demanded the lifting of US sanctions imposed for alleged money laundering and counterfeiting.

The talks have continued intermittently since 2003, but gained new urgency when North Korea conducted its atomic test.

Viktor Kremenyuk, deputy director at the USA-Canada think tank, said that Losyukov's message indicated that Russia was cutting back on longtime diplomatic support for North Korea.

"Russia's position has shifted and that could help push North Korea into a deal. They will see that no one is fighting for them," he said.

Another analyst, Anatoly Dyakov, head of the Centre for Study of Disarmament, Energy, and Ecology, said that Russia was right to toughen its stance.

"If Korea continues its nuclear programme, that will push the region out of control. Japan will be next, then Taiwan, and so on. Russia and China are worried."

Earlier this week Losyukov expressed "cautious optimism," saying that "simply the agreement to hold a new round shows that encouraging signs have appeared regarding the movement of different participants' positions."

He repeated this Wednesday, adding that both North Korea and the United States, the two countries most at loggerheads, were "now coming out with the biggest optimism."

However he tempered this with warnings about the effect of negotiations dragging on for too long with too little result.

"I personally think that this (weapon) test very much complicated the situation in the region and set back the process of the six-sided talks. The result is that we lose time and the process of nuclearisation on the peninsula goes further."

earlier related report
Seoul wants written accord from NKorea nuclear talks
Seoul (AFP) Jan 31 - South Korea said Wednesday it wants a binding written agreement to emerge from next week's six-nation talks on dismantling North Korea's nuclear weapons programme.

Foreign Minister Song Min-Soon said the new round, which starts in Beijing on February 8, should produce a document that sets out firm steps toward a nuclear-free North Korea.

Song said the round will aim to reach agreement on implementing a landmark September 2005 pact, under which the reclusive communist state agreed to abandon its nuclear ambitions in return for security guarantees, economic aid and diplomatic recognition.

"An agreement does not come in words. Lots of words have been exchanged among parties. I expect them to turn into a joint document," he told a weekly news briefing.

The United States said Tuesday it was hopeful that "substantial progress" can be made when the talks, grouping it, the two Koreas, China, Russia and Japan, resume.

The 2005 deal went nowhere after North Korea in November that year walked away from the forum in protest at US sanctions on Banco Delta Asia (BDA), a Macau-based bank accused of money-laundering for the regime in Pyongyang.

After conducting its first nuclear test on October 9 last year the North returned to the six-party talks in December. But it made it clear it would not discuss nuclear issues unless there was progress on the banking row.

US and North Korean officials began a second round of discussions on the banking curbs on Tuesday in Beijing.

"The BDA issue has so far had a negative impact on the six-party talks. I am looking forward to the settlement of the issue," Song said.

South Korea's Yonhap news agency said Sunday that North Korea would be told during the next round to dismantle its nuclear facilities within months.

The facilities subject to the shutdown include a five-megawatt reactor, a fuel reprocessing plant, a radiochemical lab and two reactors of 50 megawatts and 200 megawatts now under construction, it said.

Chun Yung-Woo, Seoul's chief envoy to the six-party talks, said Wednesday the upcoming round of negotiations should go beyond the 1994 US-North Korean nuclear disarmament deal, called the Agreed Framework.

"It will have to go slightly beyond that," he said leaving for Moscow for talks with his Russian counterpart.

"The overall concept is that the Agreed Framework was a long-term plan over 10 years. But this is not a plan for that long of a term. This will have to be short term."

The 1994 deal was scrapped after the United States accused North Korea of having run a clandestine nuclear weapons programme based on uranium enrichment.

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