Kim Jong-un says North Korea will develop more powerful weapons that ‘cannot be stopped’

North Korea’s leader Kim Jong-un has vowed to develop “more powerful” weapons, days after he oversaw the country’s biggest intercontinental missile launch.

“Only when one is equipped with the formidable striking capabilities, overwhelming military power that cannot be stopped by anyone, one can prevent a war, guarantee the security of the country and contain and put under control all threats and blackmails by the imperialists,” Mr Kim was quoted by state media KCNA as saying on Monday.

The statement comes as South Korea and other analysts fear that the North may be laying the groundwork for its first nuclear weapons test in nearly five years.

On Thursday, North Korea launched its first intercontinental ballistic missile (ICBM) since 2017, in violation of a UN ban. The missile used in the test was said to be Hwasong-17, which is known as the “monster missile” by defence analysts. The test was seen as a “significant milestone” for North Korea’s nuclear arsenal.

Mr Kim met officials, scientists, technicians and workers involved in the latest ICBM test on Monday. With the Hwasong-17 in the background during a photo session, Mr Kim pledged to build up the country’s attack capability to cope with threats.

North Korea will develop more “powerful strike means”, Mr Kim said, adding that he was confident North Korea will “more vigorously perfect the nuclear war deterrence of the country”.

Meanwhile, South Korea on Monday reiterated previous intelligence and said there were signs to show North Korea is restoring previously demolished tunnels at its underground nuclear testing site.

A government source told South Korea’s Yonhap news agency that the North is making rapid strides in preparation to carry out a nuclear weapon test and it is digging an underground “shortcut” to its nuclear test site in Punggye-ri.

“[The North] abruptly stopped its initial construction work to restore the entrance to Tunnel 3, and it is digging up the side [of the tunnel],” the source told Yonhap. “In this way, it seems like it will be possible to restore [the testing facilities] in a month.”

In March, South Korea’s military and intelligence authorities at the Centre for Non-Proliferation Studies (CNS) issued similar warnings, citing satellite images that showed signs of re-development of the underground testing facility that was shut down during negotiations in 2018.

The country conducted six nuclear weapons tests from 2006 to 2017 in the tunnels at the only nuclear test site it has in Punggye-ri. The last and largest nuclear test appeared to trigger geological instability that caused multiple small earthquakes.

But the site was shut down after North Korea’s self-imposed moratorium on nuclear and ICBM weapons tests in 2018.

Lee Jong-joo, a spokesperson at Seoul’s Unification Ministry, said that a nuclear test by North Korea now would pose “a serious threat” to international security. He urged the North to halt any related acts immediately and return to talks.

The latest test was the twelth in this year alone. Pyongyang drew widespread bafflement by releasing a bizarre Hollywood-style video of Mr Kim overseeing the North’s biggest test launch in years.

Mr Kim was seen walking out of a military-style building clad in a black leather jacket and sunglasses, with two army officers on either side, in what could be mistaken for a scene out of the 1986 film Top Gun.

The missile was said to have flown for 677 miles (1,090km) to a maximum altitude of 3,882 miles (6,248km) and hit a target in the sea between North Korea and Japan.

Additional reporting by agencies