Officials are being tight-lipped about blame until the result of an investigation into the sinking of the Cheonan is announced next week.

In the South, unofficially there is little doubt that its isolated neighbor attacked the navy corvette near their disputed sea border in March.

"We explained where the investigations are at the current stage," Kim Young-sun, South Korea's Foreign Ministry spokesman, said after talks between the Chinese and South Korean foreign ministers.

"The Chinese side commented that it had expressed its condolences for the unfortunate incident on several occasions in the past and listened to our explanations."

Chinese Foreign Ministry spokesman Ma Zhaoxu said all sides must exercise "calm and restrain to appropriately deal with the issues concerned," Xinhua said.

The talks were held on the sidelines of an East Asia conference between the top diplomats from China, Japan and South Korea.

Japanese Foreign Minister Katsuya Okada told the three-way meeting later in the day that Tokyo would oppose the resumption of six-country nuclear disarmament talks involving the North if Pyongyang is found to be the culprit.

China hosts the negotiations that would compensate the North with massive economic aid if Pyongyang takes moves to scrap its nuclear arms program, but the destitute state has boycotted the forum for more than a year.
 

China, the North's only major ally, irritated major trading partner South Korea earlier this month by hosting the reclusive North Korean leader Kim Jong-il on a rare trip abroad — before the outcome of the investigation was announced.

Seoul, its relations with the North in a deepening chill, had been hoping China would try to rein in its unruly neighbor.

But a number of analysts believe China is so nervous about a collapse of the impoverished state that it is prepared to prop up Kim's government at almost any cost.

Yonhap news agency quoted an unidentified source as saying Chinese Foreign Minister Yang Jiechi had urged a measured response against whoever may have been behind the attack.

"(Yang) stressed the importance of conducting a scientific and objective investigation," the source said.

Senior South Korean officials declined to detail Yang's comments at the meeting in the ancient capital of Shilla, the Buddhist kingdom that ruled the Korean peninsula in the first millennium.

South Korea knows it cannot launch a retaliatory strike against the North without risking greater conflict and undermining its own economy, which is just recovering from the global financial slump.

But it does want international punishment of the North. That would likely mean even tougher sanctions by the United Nations, which would need China's support to take effect.

There is media speculation in South Korea that US Secretary of State Hillary Clinton will visit Seoul later this month in a show of support over the sinking.

China last year joined the international community in UN Security Council sanctions against the North for a defiant nuclear test, hurting Pyongyang's once lucrative arms trade that was a key source of scarce hard cash.

On an unrelated note that reflected simmering tension between China and Japan that recently involved coast guard activities in waters that border them, Okada told Yang that China should cut its nuclear arsenal, a call rebuffed by the Chinese minister as grounded on unnecessary concern.