North Korea said Thursday that South Korea fabricated evidence implicating the North in a torpedo attack in order to pick on the North and any attempt at retaliating for the warship's sinking would be answered with “all-out war.” South Korean President Lee Myung-bak vowed “stern action” for the attack after a multinational investigation issued its long-awaited results Thursday, concluding the North fired a torpedo that sank the Cheonan navy ship March 26 near the Koreas' tense sea border. “If the (South Korean) enemies try to deal any retaliation or punishment, or if they try sanctions or a strike on us .... we will answer to this with all-out war,” Col. Pak In Ho of North Korea's navy told broadcaster APTN in an exclusive interview in Pyongyang. An international civilian-military investigation team said evidence overwhelmingly proves a North Korean submarine fired a homing torpedo that caused a massive underwater blast that tore the Cheonan apart. Fifty-eight sailors were rescued from the frigid Yellow Sea, but 46 perished in the South's worst military disaster since the Korean War. Since the 1950-53 war on the Korean peninsula ended in a truce rather than a peace treaty, the Koreas remain locked in a state of war and divided by the world's most heavily armed border. The truce prevents Seoul from waging a unilateral military attack. However, South Korea and the US, which has 28,500 troops on the peninsula, could hold joint military exercises in a show of force, said Daniel Pinkston, a Seoul-based analyst for the International Crisis Group think tank. South Korean and US officials also said they are considering a variety of options in response to the warship's sinking, ranging from U.N. Security Council action to additional US penalties. The exchange of war rhetoric raised tensions, but the isolated communist regime - already under international pressure to cease its nuclear weapons program - often warns of dire consequences against South Korea or Washington for any punitive steps against it. Its large but decrepit military would be no match for US and Korean forces. The impoverished country is already chafing from international sanctions tightened last year in the wake of widely condemned nuclear and missile tests. UN sanctions currently block funding to certain officials and companies, while North Korea is barred from exporting weapons and countries are authorized to inspect North Korean ships suspected of carrying illicit cargo. South Korea “will take resolute countermeasures against North Korea and make it admit its wrongdoings through strong international cooperation,” Lee said during a call with Australian Prime Minister Kevin Rudd, the presidential office said. Lee convened an emergency meeting for Friday. The White House called the sinking an unacceptable “act of aggression” that violates international law and the 1953 truce. Japanese Prime Minister Yukio Hatoyama declared his support for South Korea, calling North Korea's actions “inexcusable.” China, North Korea's traditional ally, called the sinking of the naval ship “unfortunate” but stopped short of backing Seoul. Pyongyang continued its steadfast denials of involvement in the sinking. “Our Korean People's Army was not founded for the purpose of attacking others. We have no intention to strike others first,” Col. Pak, the naval spokesman, told APTN in the North Korean capital.