North Korea's foreign ministry vowed the "toughest counteraction" against the United States as long as Washington "refuses" the country's sovereignty.

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.

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.

North Korea carried out missile tests on Saturday in the latest act of defiance from the hermit kingdom, which has been ramping up its military activity in recent months

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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.

North Korean leader Kim Jong Un vowed that Pyongyang's nuclear programme would continue "indefinitely", state media reported Wednesday, days after new US President Donald Trump said he would make

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

North Korea said Sunday it tested sea-to-surface strategic guided cruise missiles the day before, vowing to take the "toughest countermeasure" against the US in the first week of Washington's new administration.

Kim Jong Un vowed that North Korea's nuclear programme would continue 'indefinitely,' state-run media reported Wednesday, days after new US President Donald Trump said he would make renewed diplomatic overtures to the reclusive leader.

North Korea announced it had performed a test of its cruise missile system on Saturday. It was the communist country’s fourth known missile launch since November and the second in less than a week since President Donald Trump’s inauguration.