China yesterday resisted international pressure to blame North Korea for sinking a South Korean warship, and instead called for restraint on the Korean peninsula.

Speaking in South Korea, Wen Jiabao, the Chinese premier, said Beijing's main concern was stability following a March torpedo attack that sank the Cheonan warship, and claimed the lives of 46 South Korean sailors.

“The most urgent task now is to reduce the impact of the Cheonan incident to ease tensions and avoid a clash,” Mr Wen told a news conference following a summit with his Japanese and South Korean counterparts.

South Korea, the US and Japan want China to take a strong public stance over the incident, which represented the deadliest North Korean attack on the south for more than two decades.

However, China says it has not concluded who was responsible for the attack. During the summit, Mr Wen gave no indication of how China would respond when the issue was brought to the United Nations security council.

South Korea and the US have provided China with technical details on the sinking and have offered more information. Seoul also says it is open to a visit from any Chinese technical team that may wish to inspect the shattered hull and corroded torpedo, which it says was fired from a North Korean submarine.

South Korean officials admitted before the summit they had little hope Beijing would publicly condemn its communist ally. Instead, they expected to begin talks aimed at persuading China not to veto a strong condemnation of North Korea at the security council.

While Seoul is leaving open the option of fresh sanctions, officials admit that North Korea is already so heavily sanctioned over its missile and nuclear weapon programmes that any other measures would have little practical effect.

On Friday, a South Korean government spokesman quoted Mr Wen as saying that Beijing would not protect “whoever sank the ship”. However, Mr Wen did not strike such an encouraging tone for the South Koreans when he spoke to them directly.

Yukio Hatoyama, Japan's prime minister, has supported South Korea's assertive response to the sinking, calling the attack “provocative” and “unforgivable”.

Mr Hatoyama has authorised a plan to restrict cash remittances to North Korea from ethnic Koreans in Japan, long an important source of foreign currency for Pyongyang. Japan will require travellers to North Korea to declare cash holdings exceeding Y100,000 ($1,110, €890, £760), down from the current Y300,000.

Electronic remittances exceeding Y3m will also have to be declared, down from Y10m. Japan's parliament is also working on a bill that would allow Japanese coastguards to inspect North Korean cargo ships in international waters.

South Korean officials have played down the possibility of a conflict with North Korea, despite heated rhetoric from Pyongyang, in an effort to reassure investors.

Wi Sung-lac, South Korea's most senior diplomat on North Korean affairs, told investors before the talks that the road to condemnation at the UN could be long. He also warned against expecting any “tangible” results at the summit, being held on the resort island of Jeju.