North Korea fired three medium-range ballistic missiles into the sea off its east coast Monday, landing close to Japan, in a show of force that coincided with the meeting of leaders of the world’s 20 largest economies in neighboring China. “We are fully prepared to fight tonight in case North Korea makes any provocative moves,” an official from South Korea's joint chiefs of staff added, according to the Yonhap News Agency, using the catchphrase of the American and South Korean military allies. At the G-20 meeting, South Korean President Park Geun-hye and Japanese Prime Minister Shinzo Abe met immediately and agreed to cooperate against North Korea.