Defense Secretary Frank Carlucci today accused North Korea of trying to disrupt the Olympic Games and said the United States would beef up its military forces to stop any threat. ``Let me assure you that we will do all we can to help ensure the security of the 1988 Summer Olympics Games,'' he said. Communist North Korea continues to threaten peace on the divided Korean peninsula by refusing to work with South Korea to defuse the tension, Carlucci said. ``It is most unfortunate that the north continues its trouble-making role and remains unwilling to make the simple concessions necessary to bring about a reduction in tensions on the peninsula,'' he said. Carlucci gave the assurance to South Korean defense officials at the start of the 20th annual U.S.-South Korea security conference to discuss mutual defense. South Korea Defense Minister Oh Ja-bok also stressed the North Korean threat to the south and said the Olympics was adding to the tension. ``With the danger of their scheme to disrupt the coming Olympics remaining undiminished, military tension between south and north on the peninsla continues, thus posing a grave threat to the stability of Northeast Asia,'' he said. U.S. and South Korean delegates agreed during the talks to build up their early warning systems to detect any possible North Korean military threat. Up to three U.S. Navy aircraft carriers will help provide security for the Games, officials said. North Korea is demanding to co-host the Olympics. The International Olympic Committee and South Korea have rejected the demand, saying the Games are awarded to a single city. The two Koreas, divided since 1945, are bitter opponents that have clashed repeatedly. The United States has about 42,000 U.S. troops based in the south under a mutual defense pact. After meeting with Oh, Carlucci had lunch with President Roh Tae-woo and was awarded the Order of National Security. His scheduled visits later in the day with frontline American and South Korean troops were canceled due to bad weather, officials said.