North Korean flag. (Wikimedia Commons)

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The state-run Korean Central News Agency said North Korea plans to "readjust and restart all nuclear facilities" at the nation's main nuclear complex in Yongbyon. The complex, which includes a uranium enrichment facility and a reactor, has been inactive since October 2007 when a nuclear disarmament deal was reached between the North, the United States, and four other nations. According to the Washington Post, experts who have visited the facility say the reactor is intended for producing weapons-grade plutonium, and once the facility is fully operational the plant could produce enough plutonium for one bomb a year. 

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South Korean United Nations Secretary-General Ban Ki-moon said, "The current crisis has already gone too far. Nuclear threats are not a game. Aggressive rhetoric and military posturing only result in counter-actions, and fuel fear and instability. Things must begin to calm down, as this situation, made worse by the lack of communication, could lead down a path that nobody should follow." 

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This announcement comes after weeks of threats against the U.S. and South Korea from North Korea's leader Kim Jong-un. The threats started after the U.S. and South Korea began running joint military exercises. On Sunday, according to the New York Times, the ruler said the North's nuclear weapons "are neither a political bargaining chip nor a thing for economic dealings." 

CNN reports that analysts believe North Korea's rhetoric far outweighs the country's current nuclear capabilities. 

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University of Seoul North Korean expert Hwang Jihwan told Fox News, " North Korean is keeping tension and crisis alive to raise stakes ahead of possible future talks with the United States. North Korea is asking the world, 'What are you going to do about this?'"