North Korean leader Kim Jong Un called for bolstering nuclear forces this year during a visit to the country's nuclear material production base and nuclear weapons institute, state media KCNA said on Wednesday.

South Korea 's Yonhap News Agency said North Korea might be using a vertical cold-launch system to fire the missiles. The system, which is commonly associated with submarine- and ship-based weapons, ejects a missile from its container before the missile ignites midair.

The dictator, eager to shut out the influence of Hollywood and K-pop, has been exalting a “shock brigade” of 300,000 teens and 20-somethings drafted into flood reconstruction.

North Korea says it tested a cruise missile system, its third known weapons display this year, and vowed “the toughest” response to what it called the escalation of U.S.

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North Korea has test-fired sea-to-surface strategic cruise guided missiles, the North's state media reported Sunday, quoting Kim as saying that Pyongyang's deterrence means are being perfected.