North Korea has staged a "simulated tactical nuclear attack" drill at the weekend with mock atomic warheads attached to two long-range cruise missiles that were test-fired into the ocean, state-controlled media reported.
The Korean Central News Agency [KCNA] said on Sunday the operation on early Saturday was a "counteraction drill" in response to joint military activity by US and South Korean forces that KCNA said has escalated tensions in the region.
"A firing drill for simulated tactical nuclear attack was conducted at dawn of September 2 to warn the enemies of the actual nuclear war danger," KCNA reported.
"Two long-range strategic cruise missiles tipped with mock nuclear warheads were fired" from North Korea's west coast, into the sea to the south, it said.
A separate statement said Leader Kim Jong-un visited the Pukjung Machine Complex, which produces marine engines, and a major munitions factory to stress the importance of strengthening Pyongyang's naval forces.
"He affirmed that a future plenary meeting of the Central Committee of the WPK [Worker's Party of Korea] would set forth an important modernisation of the complex and the development direction of the shipbuilding industry," the KCNA statement said.
South Korea's Joint Chiefs of Staff said on Saturday that an unspecified number of cruise missiles were launched at around 4:00 am towards the Yellow Sea, adding the specifications of the missiles were being evaluated.
KCNA said the United States and South Korea were pursuing "confrontation hysteria" with their latest joint military drills.
Ramping up arsenal
North Korea has conducted a record number of weapons tests this year, and last week carried out its second failed attempt to put a spy satellite into orbit.
Seoul and Washington have ramped up defence cooperation in response, staging joint military exercises with advanced stealth jets and US strategic assets.
On Tuesday, Kim visited a training command post where he detailed future war plans, including "making simultaneous super-intense strikes" at core military posts in the South.
Relations between the two Koreas are at their lowest point in years, and diplomacy is stalled after failed attempts to discuss Pyongyang's denuclearisation.