Kim urges N Korean experts to produce "powerful nuclear weapons"

Pyongyang [North Korea], March 28 : Kim Jong Un maintains that his development of nuclear weapons is focused on defending North Korea against a hostile US and South Korea.
North Korea's leader Kim Jong Un has called on his country's scientists to expand production of "weapon-grade nuclear materials" and build more powerful weapons, state media reported.
Kim's latest calls, a reiteration of an earlier promise to ramp up nuclear weapons production "exponentially", came ahead of a United States Navy carrier strike group's scheduled arrival in South Korea on Tuesday, Al Jazeera reported.
North Korea's official Korean Central News Agency (KCNA) reported on Tuesday that Kim, in a briefing with officials from his nuclear weapons institute, said that North Korea should prepare to use its nuclear weapons "anytime and anywhere".
"We should never be satisfied with the work to consolidate the thoroughgoing response posture of our nuclear force and should continuously strive to strengthen nuclear force steadily," Kim was quoted as saying by KCNA, according to South Korea's Yonhap News Agency.
Kim called on his officials to "expand on a far-sighted way the production of weapon-grade nuclear materials for thoroughly implementing the plan ... on increasing nuclear arsenals exponentially". He also told his officials to "put spurs to continuing to produce powerful nuclear weapons", KCNA reported.
North Korea last year declared itself an "irreversible" nuclear power and Kim recently called for an "exponential" increase in weapons production, including tactical nuclear weapons, Al Jazeera reported.
According to the KCNA report on Tuesday, Kim was also briefed on an IT-based integrated nuclear weapon management system called Haekbangashoe, which means "nuclear trigger". The system's accuracy, reliability and security were verified during recent drills simulating a nuclear counterattack, the news agency added.
South Korea's Yonhap reported that North Korean media also released photographs for the first time of Kim inspecting what appeared to be tactical nuclear warheads known as the Hwasan-31.
"Photos showed around 10 tactical nuclear warheads lining up, with an apparent intent to show that the country could put such warheads on super-large multiple rocket launchers or cruise missiles targeting South Korea," Yonhap reported.
The USS Nimitz aircraft carrier arrived in the South Korean port of Busan on Tuesday after the United States conducted exercises in international waters with South Korea's navy, Al Jazeera reported.
Al Jazeera's report from Busan said that the nuclear-powered USS Nimitz, which is one of the largest warships ever built, is taking part in extensive exercises with South Korean forces after a hiatus of a number of years to first allow dialogue with North Korea and then due to COVID-19.
In a separate news report on Tuesday, KCNA said that North Korea had conducted the first test of a new underwater weapon called Haeil -- tsunami in Korean -- which was carried out last week in what Pyongyang said was a response to the recent US-South Korea military exercises, the largest in scale in five years.
The Haeil manoeuvred underwater "for 41 hours and 27 minutes tracking a simulated route spanning 600 kilometres" before detonating on a target off the coast of North Hamgyong province early Monday, KCNA said.
The same report also carried details of what North Korea described as drills that simulated tactical nuclear strikes that detonated above targets, Yonhap reported.
According to KCNA, ground-to-ground tactical ballistic missiles were used in "nuclear air explosion" exercises, which involved mock nuclear warheads detonating in the air 500 metres above an intended target island, Yonhap reported.
Kim said the policy of expanding North Korea's arsenal was solely aimed at defending the country as well as regional peace and stability, KCNA added.
Pyongyang has blasted Seoul and Washington over their regular joint military exercises, saying the drills had pushed the situation on the Korean peninsula to an "extreme red line", Al Jazeera reported.
North Korea for decades has described the US's joint military exercises with South Korea as rehearsals for a potential invasion, although the allies have described those drills as defensive. North Korea last year ramped up its own weapons demonstrations as the allies resumed their large-scale training that had been downsized for years, Al Jazeera reported.