N Korea says simulated 'scorched earth' nuclear strikes on South

North Korea has said its latest missile launches simulated “scorched earth” nuclear strikes on South Korea and that it’s also been rehearsing an occupation of its rivals’ territory in the event of conflict.

Pyongyang has previously tested nuclear-capable missiles and described how it would use them in potential wars with South Korea and the US.

But the North's disclosure of detailed war plans reaffirmed its aggressive nuclear doctrine to intimidate its opponents as it escalates its protest of the ongoing South Korean-US military exercises that it views as a major security threat, observers say.

North Korea’s military said it fired two tactical ballistic missiles from the capital on Wednesday night to simulate “scorched earth strikes” at major command centres and operational airfields in South Korea, according to the official Korean Central News Agency on Thursday.

The North’s military said the missiles carried out their simulated strikes through air bursts, suggesting it confirmed the explosions of dummy warheads at a set altitude.

North Korea said its missile tests were a response to the United States’ flyover of long-range B-1B bombers for joint aerial training with South Korea earlier Wednesday as part of the allies’ field exercises.

“(The aerial drill) is a serious threat to (North Korea) as it was just pursuant to the scenario for a preemptive nuclear strike at” North Korea, the Korean People's Army general staff said. “The KPA will never overlook the rash acts of the U.S. forces and the (South Korean) military gangsters.”

The missile launches Wednesday were the latest in the North’s barrage of weapons tests since last year.

According to South Korean and Japanese assessments, the two short-range missiles travelled a distance of 360-400 kilometres (225-250 miles) at a maximum altitude of 50 kilometres (30 miles) before landing in the waters between the Korean Peninsula and Japan.

South Korea’s Joint Chiefs of Staff called the launches “a grave provocation” that threatens international peace and violates UN Security Council resolutions that ban any ballistic launches by North Korea.

The US Indo-Pacific Command said the US commitment to the defence of South Korea and Japan remains “ironclad”.

South Korean and Japanese authorities said their warplanes conducted combined aerial drills with US B-1B bombers on Wednesday. South Korea’s Defence Ministry said that Wednesday’s B-1B deployment is the 10th flyover by US bombers on the Korean Peninsula this year.

North Korea is extremely sensitive to the deployment of US B-1B bombers, which can carry a huge number of conventional weapons. The North describes the bombers as “nuclear strategic,” although the planes were switched to conventional weaponry in the 1990s.

On Aug. 21, the US and South Korean militaries kicked off their summer Ulchi Freedom Shield computer-simulated command post exercise. During this year’s training, slated to end later Thursday, the allies have included more than 30 kinds of field exercises, such as Wednesday’s joint aerial exercise involving the B-1B aircraft.

North Korea calls major U.S.-involved military drills on and near the Korean Peninsula as an invasion rehearsal.

North Korea has openly threatened to use its nuclear weapons first in potential conflicts with South Korea and the US since it last year adopted a new law that authorised the preemptive use of nuclear weapons in a broad range of situations.

Kim has been pushing hard to expand and modernise his weapons arsenals. Its second attempt at launching a spy satellite failed last week, but it plans a third attempt in October.

Foreign experts say Kim eventually wants to use his enlarged weapons arsenals to force the US to make concessions when diplomacy resumes.