The Associated Press: US diplomat: US-Japan pact vital in changing Asia TOKYO â€” The top U.S. diplomat for East Asia said Wednesday that Washington and Tokyo need to make sure their security alliance is in good working order to cope with rapid changes in Asia. U.S. Assistant Secretary of State Kurt Campbell also praised Prime Minister Naoto Kan for demonstrating "statesmanship" in his handling of a spat with China over disputed islands in the East China Sea. Campbell's visit, to prepare for a trip by President Barack Obama to Japan in November, comes as an increasingly confident China expands its military and maritime activities in disputed waters and North Korea pursues its nuclear and missile programs. "We're living through a period of very consequential developments, not just in Northeast Asia, but Asia as a whole, and it's extremely important that the U.S.-Japan relationship not be left behind, and that we focus attentively on the changing security environment," Campbell told a small group of reporters at the U.S. Embassy. "It is critical for this generation of American policymakers to in no way take Japan for granted," he added. Relations between Tokyo and Washington soured somewhat earlier this year under Kan's predecessor, who attempted to move a controversial U.S. Marine base out of Okinawa, contrary to a previous agreement with Washington. The two sides agreed in May to stick with the original plan and shift Marine Air Station Futenma to a less-populated part of the island, but strong local opposition has stalled progress in carrying it out. "The desire to successfully conclude an agreement and move forward is high in Washington," Campbell said. "We've conveyed that sense of urgency directly to Japanese colleagues." Under the U.S.-Japan security alliance, in its 50th year, some 47,000 American troops are stationed in Japan. The U.S. is obliged to respond to attacks on Japan and protects the country under its nuclear umbrella. Campbell said the U.S. did not play a role in facilitating dialogue between China and Japan in their dispute over the arrest of a Chinese fishing boat captain whose vessel collided with Japanese patrol boats near islands claimed by both nations. Japan eventually released the captain, but his detention stirred up nationalism in both countries and raised tensions. Tokyo has declared an end to the spat over the collision, but the territorial dispute itself has not been resolved â€” and Campbell suggested that more might arise. "As both countries are increasingly reliant on freedom of navigation, freedom of the oceans, it seems that coming to terms with these issues will be essential going forward," he said. Campbell praised Kan's handling of the incident to keep it from spinning out of control. "He saw the potential for a dramatic degradation in relations, recognized that it wasn't in the interest in Japan â€” and frankly of China or other countries in Asia â€” and he took the necessary steps, and we praised him within that context." Campbell also said the U.S. could help create an environment in which rival claimants in territorial disputes could discuss how to resolve their differences. Beijing was furious after U.S. Secretary of State Hillary Rodham Clinton told a regional security forum in July that the peaceful resolution of disputes over the Spratly and Paracel island groups in the South China Sea was in the American national interest. Beijing said Washington was interfering in an Asian regional issue. "I don't think it would be an appropriate role for the United States to play a direct role" in resolving such disputes, Campbell said. "In the South China Sea, there is no desire by any of the claimants for the United States to play such a role. What they want is for the United States to support a process" that would resolve disputes, he said. Campbell heads to Seoul on Thursday.