Analysis: N.Korea's call for talks hardly welcome by South, U.S.

SEOUL (Reuters) - North Korea, which escaped U.N. censure over the sinking of a South Korean warship, is signaling it wants to restart nuclear weapons negotiations. For the United States and South Korea, the talks are fraught with risk.

Washington is well aware of the political mileage it gives the hermit state by sitting at the same negotiating table. The question is how to avoid simply letting Pyongyang go through the motions only to later renege, again, on promises to roll back its nuclear arms programme.

And South Korean President Lee Myung-bak, who in a tearful nationwide address pledged to seek revenge for the ship sinking, will want to avoid being seen as giving in to North Korea which it says torpedoed the Cheonan warship in March, killing 46 sailors.

The U.N. Security Council last week condemned the sinking of the Cheonan but, to ensure support from China which is the Pyongyang's only powerful ally, did not name North Korea.

In the end, analysts say Seoul and Washington have little choice but to heed China's urging to return to six-party nuclear talks that the North has boycotted for the past 1- years.

"They know there is no other way; there's no other exit," said Paik Hak-soon, an expert on the North's negotiating tactics at the Sejong Institute.

"Denuclearization of the North through the six-party talks has become a much more seriously difficult problem."

The talks include the two Koreas and regional powers China, Japan, Russia and the United States.

For Pyongyang, the talks are one of its few chances to leverage benefits from what it sees as a hostile world that has largely isolated it over a series of missile and nuclear tests.

But years of negotiation to convince it to scuttle its nuclear ambitions in exchange for generous aid and an end to its pariah status, have achieved little.

Analysts say U.S. concerns are increasingly focused on preventing North Korea exporting any atomic weaponry.

"The U.S. has been looking at the anti-proliferation aspect of the six-party talks as opposed to Denuclearization of North Korea," said Yang Moo-jin of the University of North Korean Studies in Seoul. "To some degree, it understands that it would be very difficult to get the North to denuclearize completely.

"The U.S. approach to the nuclear talks with the North is in the context of its policy on a world without nuclear weapons. As it deals with Iran and trying to get Iran to drop its nuclear ambitions, getting the North to do the same is important."

SCEPTICAL OF PYONGYANG AND BEIJING

South Korea too has little choice but to return, albeit reluctantly, to the talks, almost the only forum it has left to talk directly to the North.

"We've had almost seven years of negotiations with the North for ending its nuclear programme. So more than the fact that the North is returning to the talks ... what is important is how serious is the North's commitment to Denuclearization," Foreign Ministry spokesman Kim Young-sun said.

The South has yet to implement the toughest retaliatory measures it originally promised, including a massive joint naval exercise with the United States and loudspeaker broadcasts at the border. The North said it would shoot the loudspeakers.

"The Lee Myung-bak government is in a dilemma over whether to engage in dialogue with the North to achieve stability on the Korean peninsula or to try to change the North by applying pressure," said Yang of the University of North Korean Studies.

"Now that the U.N. Security Council recommended dialogue as a way to ease tension, the government will feel the pressure to try dialogue."

(Additional reporting by Ben Blanchard in Beijing, editing by Jonathan Thatcher)