SEOUL: The United States' point man on North Korea arrived in Seoul Tuesday, calling for ‘serious negotiations' to ease tensions over Pyongyang's nuclear program and deadly attack on a South Korean island. Ambassador Stephen Bosworth, the US special representative for North Korea policy, said he would closely coordinate with South Korea and China on how to deal with Pyongyang. “We believe that serious negotiations must be at the heart of any strategy for dealing with North Korea and we look forward to being able to launch those at a reasonably early time,” he told reporters at the airport. China has proposed bringing together the envoys of long-stalled six-nation disarmament talks on the nuclear-armed North to defuse tensions. But Seoul, Washington and Tokyo have been lukewarm to the idea, saying Pyongyang first needs to show it is sincere about denuclearisation and mending ties with Seoul. “I will let the Chinese speak for themselves on that. I think, by and large, we've been working together with them very effectively. That's an important relationship for both countries,” Bosworth said. The envoy is scheduled to meet his South Korean counterpart, Wiung-Lac, and Foreign Minister Kim Sung-Hwan Wednesday before flying to Beijing. Cross-border tensions have been high since the North shelled a South Korean island on November 23, killing four people including two civilians. The North also raised security fears that month by disclosing a uranium enrichment plant to visiting US experts. It has insisted the plant is designed solely to fuel a light-water reactor being built to produce energy. But US officials and experts say this could easily be converted to produce weapons-grade uranium. – Agence France