North Korea on Friday fired a short-range ballistic missile, conducted an artillery barrage, and flew fighter jets close to the South's border in another show of force that the US has warned could culminate in a nuclear test.
Pyongyang has dramatically ramped up missile launches and military exercises in recent weeks, which it now describes as "tactical nuke" drills, as Seoul and Washington say Kim Jong Un is close to conducting what would be his country's seventh nuclear test.
North Korea's military said in a rare statement its latest actions came in response to a "provocative" South Korean artillery exercise near the border.
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The Korean People's Army "took strong military countermeasures," according to a statement carried by the official Korean Central News Agency early Friday.
Pyongyang issued "a stern warning to the South Korean military inciting military tension in the frontline area with reckless action," said the statement.
South Korea's military said it had detected the ballistic missile launch from the Sunan area in Pyongyang early Friday, just hours after Pyongyang flew 10 fighter jets close to the inter-Korean border.
The North Korean jets crossed a Seoul-set "reconnaissance line" which triggers an automatic operational response. Seoul then scrambled military aircraft, including F-35A fighter jets, the Joint Chiefs of Staff said.
North Korea also fired some 170 artillery shots into waters off its east and west coasts, violating a maritime "buffer zone" agreed in a 2018 deal, JCS said.
Seoul's National Security Council condemned what it described as a barrage of "hostile actions" overnight, warning in a statement that "such provocations will bring consequences".
The South also imposed its first unilateral sanctions in five years Friday, targeting North Korean individuals and institutions.