President Hu Jintao and his United States counterpart Barack Obama discussed the situation on the Korean peninsula in a telephone call yesterday, according to state media.

While the Xinhua News Agency gave no details, AP reported that the move "comes amid efforts by the US to enlist Chinese support for a tough new UN Security Council resolution in response to" the Democratic People's Republic of Korea (DPRK)'s nuclear test.

Pyongyang claims to have conducted a nuclear test on May 25 and test-fired a series of short-range missiles over the last week, in violation of UN sanctions. World powers have since huddled together to chalk out a decisive response to DPRK's moves. Any UN Security Council response will have to be endorsed by China and Russia. Both have expressed "the necessity of a convincing response from the Security Council" but believe that "resolving the problem is only possible on political-diplomatic tracks".

While some experts feel China is being cautious, others feel Beijing's opposition to possible Security Council sanctions would embolden DPRK leader Kim Jong-il further.

"The move by China and Russia will lead to a very bad outcome," said Zhang Liangui, a senior researcher on East Asia Studies at the Party School of the Communist Party of China Central Committee. "If there are no further sanctions (against the DPRK), it would be like telling Kim Jong-il to do as he likes," said Zhang.

China had backed a UN resolution condemning Pyongyang's first nuclear test in 2006. But it fended off demands for sanctions that would choke Pyongyang's economy.

It is likely, say experts, that Chinese leaders would be "more cautious" to support strong sanctions this time.

"China's aim is to avoid the collapse of Six-Party Talks," said Xu Guangyu, secretary of China Arms Control and Disarmament Association. "Excessive sanctions won't help achieve that goal."

Xu predicted that while China may have to compromise to the US at the Security Council, it "would not support tough sanctions".

Liu Jiangyong, an expert on East Asian security at Tsinghua University in Beijing, too said China would be extremely cautious. "China won't agree to excessive sanctions. That would only stoke conflict with Pyongyang," said Liu.

Rear Admiral Yang Yi, senior researcher at the National Defense University, said the issue can be resolved through political and diplomatic measures. "Don't shut the door," Yang said, without specifying whether China should support or oppose sanctions.

Shen Dingli, executive dean of the Institute of International Studies at Shanghai-based Fudan Univerisity, said: "A sanction is intervening into other country's domestic affairs, (so it's) against the basic principle of China's diplomacy."