A US guided-missile submarine arrived in South Korea today and envoys from the US, Japan and South Korea met in Tokyo, as North Korea prepared to mark the anniversary of the founding of its military. Although a major event around the anniversary was viewed as possible, the morning came and went without any nuclear tests or ballistic missile launches. All that was publicly scheduled for the day were gatherings for mass dancing, a common celebration on major North Korean holidays. At a 'national meeting'\u00a0of thousands of senior military and civilian officials the day before, North Korea's Minister of Defense Gen Pak Yong Sik reiterated that the country is ready to use pre-emptive strikes or any other measures it deems necessary to defend itself against the "US imperialists." "The situation prevailing on the Korean peninsula is so tense that a nuclear war may break out due to the frantic war drills of the US imperialists and their vassal forces for aggression," he told the gathering. North Korean leader Kim Jong Un did not attend. It was not known how he was marking Tuesday's anniversary. North Korea often marks significant dates by displaying its military capability and has conducted five nuclear tests. Pyongyang launched a missile one day after the 105th birthday of late founder Kim Il Sung on April 15. Such a move could test the developing North Korea policies of President Donald Trump, who has reportedly settled on a strategy that emphasizes increased pressure on North Korea with the help of China, the North's only major ally, instead of military options or trying to overthrow North Korea's government. You might also want to see this: The nuclear-powered USS Michigan submarine arrived at Busan in what was described as a routine port visit to rest the crew and load supplies. Commander Jang Wook from the South Korean navy public affairs office said there is no plan for any drill. The submarine's arrival comes as the USS Carl Vinson aircraft carrier heads toward the Korean Peninsula in a show of force. In Tokyo, US representative for North Korea Policy Joseph Yun was meeting Tuesday with his Japanese counterpart Kenji Kanasugi and Kim Hong-kyun of South Korea. Japan's Chief Cabinet Secretary Yoshihide Suga told reporters that the three envoys were to deepen cooperation and stay on the same page amid growing tension. Japan's Foreign Ministry also announced that China's envoy for North Korea, Wu Dawei, will visit Tokyo on Tuesday for talks with Kanasugi, which may take place later this week. Trump spoke by phone with both the Japanese and Chinese leaders yesterday. Chinese state broadcaster CCTV quoted President Xi Jinping as telling Trump that China strongly opposes North Korea's nuclear weapons program and hopes "all parties will exercise restraint and avoid aggravating the situation."