North Korea's foreign minister left for Russia Saturday amid a flurry of diplomatic attempts to ease tensions following the North's deadly attack on a South Korean island last month.

Pak Ui-Chun departed for Moscow, the North's official news agency said, a day after defending his country's move to strengthen its nuclear weaponry.

Pyongyang is "assured of the rectitude of our choice of the songun (army first) policy, and in strengthening a defence that relies on nuclear forces for deterrence," he told Russia's Interfax news agency.

Pak repeated assertions that US hostility and South Korea's confrontational policy had left the Korean peninsula situation in "quite a dangerous stage".

The North's November 23 bombardment of a border island killed four people including civilians and triggered a regional crisis.

It also highlighted divisions between China, the North's sole major ally and key food and fuel source, and the United States on ways to restrain the hardline regime.

Washington and its ally Seoul have staged joint naval exercises to deter Pyongyang and threatened a tough response to any future attacks. Beijing sent a senior official for talks with the North's leader Kim Jong-Il.

State Councillor Dai Bingguo and Kim reached agreement Thursday on Korean peninsula issues, China's news agency reported without elaborating.

China has briefed South Korea on that meeting, a Seoul official told Yonhap news agency on condition of anonymity.

"I can't speak in detail, but regarding North Korea's position, it appears that there is little difference in the position that it has been sticking to," the official said.

The North says it fired in response to a South Korean artillery drill that dropped shells into its waters near the contested border. The South says the North's attack was pre-planned.

US Deputy Secretary of State James Steinberg is scheduled to visit Beijing in the coming week to press the Chinese for stronger action.

And South Korea's chief nuclear envoy will visit Russia for talks with his counterpart Alexei Borodavkin, Seoul's foreign ministry said.

Wi Sung-Lac will discuss the shelling and the North's disclosure last month of an apparently operational uranium enrichment plant.

The North says the plant is part of a peaceful energy programme but US officials say it could be configured to produce weapons-grade uranium.

China has called for an emergency meeting on the crisis between chief delegates to stalled six-party talks on the North's nuclear disarmament.

The United States, Japan and South Korea have reacted coolly, saying the North must first mend ties with the South and show it is serious about disarmament.

Russia is the sixth member of the forum.

"We need to think about creating conditions to restart talks between the six parties," its deputy nuclear negotiator Grigory Logvinov told Interfax Friday.

Pak said Pyongyang was always ready to negotiate.

"Even in the atmosphere of the escalated situation, we have expressed support of resuming the six-party negotiation process," he said.

Saturday also saw China's chief nuclear envoy, Wu Dawei, hold talks with his Japanese counterpart Akitaka Saiki in Beijing, the Kyodo news agency said.

Wu again stressed China's stance that an emergency meeting of the six powers would help defuse tension on the Korean peninsula, the report said.

New Mexico Governor Bill Richardson meanwhile is to visit North Korea in the coming week in an attempt to lessen tensions.

Richardson, who has visited the North several times previously in a trouble-shooting role, has said his December 16-20 visit is private but he hopes "to be helpful during this volatile period".