Moscow also said resumption of the long-stalled talks and diplomatic solutions are the only viable options available to both deal with the nuclear issue in the region and to lift UN sanctions against the DPRK, which is prohibited from conducting launches that use ballistic missile technology.

However, Moscow also said it had never denied the DPRK's sovereign right to pursue peaceful space programs and urged all parties involved to exercise maximum restraint.

The US and the ROK have tried to use the nuclear security summit to draw attention to the Korean Peninsula nuclear issue and put more pressure on the DPRK.

Given China's influence, Obama "felt it was very important for us to be working closely with China and for China to be sending a very strong message to DPRK", Ben Rhodes, a deputy national security adviser was quoted by AFP as saying.

Hu's comments showed China shared concerns on the situation with other countries and was determined to reach a peaceful solution, said Wang Junsheng, an expert on Asian studies at the Chinese Academy of Social Sciences.

"China is the only country which has a stable relationship with all the other members of the Six-Party Talks, so China's mediation among them is extremely important," Wang said.

"The situation on the Korean Peninsula is not likely to get out of control, because all parties want to ease tension."

The situation is very fragile, due to different factors, said Shen Dingli, an expert on international relations with Shanghai-based Fudan University.

The two presidents also discussed the Iranian nuclear issue, with both welcoming upcoming diplomatic efforts by the "P5 plus One Group" to end the nuclear standoff.

The group, the five permanent members of the UN Security Council plus Germany, is trying to broker a solution but Obama warned earlier on Monday that "time is short".

Hu urged that the US should continue to adhere to the policy of engagement to solve the Iranian nuclear issue.

"China does not approve of the development of nuclear weapons by Iran or any country in the Middle East, and China believes that dialogue and negotiation are the only right way to resolve the issue," Hu said.

Contact the writers at wujiao@chinadaily.com.cn and zhouwa@chinadaily.com.cn