China on Monday dismissed a media report stating that the Democratic People's Republic of Korea had informed Beijing of plans to carry out more nuclear tests.

A Foreign Ministry spokesman warned against any actions that could worsen the situation on the Korean Peninsula.

Diplomacy is ongoing amid tensions on the peninsula. Japan will send a veteran diplomat to China for three days from Tuesday, according to Japan's Kyodo News Agency.

Observers said averting a looming crisis requires a restrained approach, and more attention should be paid to diplomacy.

Spokesman Hong Lei said he "did not know where the Reuters report came from" when asked to confirm the report on Friday.

The story said the DPRK had told China that it is prepared to carry out one or even two more nuclear tests, or another rocket launch this year.

The current situation of the peninsula is "sensitive and complicated", and China calls on relevant parties to exercise calm, Hong said.

Yu Meihua, director of the Center for Korean Peninsula Peace Studies under the China Reform Forum, said relevant parties should "remain cautious" with their rhetoric and actions to avoid further escalation.

"In light of the strained regional situation, fueling the 'fire' should be avoided, and the situation needs to be cooled down," Yu said.

The DPRK conducted its third nuclear test on Feb 12 despite strong opposition from the international community. Hong on Monday reiterated that China opposes the test.

The participants of the Six-Party Talks, including China, the Republic of Korea, the United States, Russia and Japan, should lobby the DPRK to return to talks first, Yu Meihua said.

China holds that the UN Security Council's relevant discussions should be conducive to the realization of denuclearization, non-proliferation and peace and stability on the peninsula, Hong said. The spokesman added that China is ready to maintain contacts with all relevant parties.

Shinsuke Sugiyama, director-general of the Japanese Foreign Ministry's Asian and Oceanian Affairs Bureau, will talk about the peninsula issue in Beijing this week, Kyodo reported.

Shinsuke is reportedly going to hold talks with Wu Dawei, China's special representative for Korean Peninsula affairs, the agency reported.

The Japanese Foreign Ministry declined to discuss whether he would meet with his Chinese counterparts, according to AFP.

Zhang Tuosheng, a researcher at the China Foundation for International and Strategic Studies, said parties including Seoul, Washington and Tokyo should also keep calm and restrained in comments because dialogue is more ideal than a war.

"The tension will definitely go on for a period of time, and dialogues may be achieved after enduring bargaining and gaming," Zhang estimated.

Meanwhile, Seoul and Washington will kick off a six-day naval drill on Tuesday to test their combat readiness, the ROK's Joint Chiefs of Staff said in a statement on Monday.

The drills will involve about 10 warships from Seoul, including Aegis destroyers, submarines and other surface combatants, as well as the US P-3 maritime patrol aircraft, to conduct anti-submarine warfare exercises, Yonhap News Agency said.

Military drills are not favorable for regional peace and stability, and accidental major conflicts should be ruled out, Zhang Tuosheng said. "Military trainings have been a routine step (in times of tension)."

Seoul has been maintaining high military alert and close surveillance of Pyongyang to "monitor signs of additional nuclear tests or provocations", the ROK Defense Ministry said on Monday.

Liu Jiangyong, a professor of international relations at Tsinghua University, said history has proven that when Washington and Seoul carried out the so-called sunshine policy toward the DPRK, tensions on the Korean Peninsula would be eased, which would provide conditions for realizing denuclearization.

Xinhua contributed to this story.