South Korea's chief nuclear negotiator will fly to Beijing later Tuesday to meet his Chinese counterpart, officials said, amid hopes that stalled talks with North Korea may soon resume.  "Chief delegate Kim Sook is leaving for Beijing today and is expected to stay there for three days," a foreign ministry official told AFP on condition of anonymity. "He is expected to meet with his Chinese counterpart to discuss the North Korean nuclear issue," the official added without elaborating. Last week the North gave a US team some 18,000 pages of documents on the history of its plutonium bomb-making programme dating back to 1986.