North Korean leader Kim Jong Un has vowed to develop more powerful means of attack, days after the country’s first intercontinental ballistic missile (ICBM) launch in more than four years.

The statement suggests North Korea might perform additional launches or even test a nuclear device soon as it pushes to modernise its arsenal and increase pressure on the US administration while nuclear diplomacy remains stalled.

Last Thursday, the North performed its 12th round of weapons tests this year, launching the newly developed, long-range Hwasong-17, which analysts say was designed to reach anywhere in the US mainland.

During a photo session with scientists and others involved in the Hwasong-17 test, Mr Kim expressed a resolve to build up the country’s attack capability to cope with threats, according to the official Korean Central News Agency (KCNA).

“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,” KCNA quoted Mr Kim as saying.

North Korea Koreas Tensions
A test-fire of a Hwasong-17 intercontinental ballistic missile (Korean Central News Agency/Korea News Service via AP)

Mr Kim said North Korea will develop more “powerful strike means” and also expressed his conviction and expectation that his country will “more vigorously perfect the nuclear war deterrence of the country”, KCNA said.

North Korea said the Hwasong-17 flew to a maximum altitude of 3,880 miles and travelled 680 miles during a 67-minute flight before landing in waters between the Korean Peninsula and Japan.

Outside experts said if the missile is fired on a standard trajectory, flatter than the steep test angle, it could fly as far as 9,320 miles, enough to reach anywhere in the US mainland and beyond.

Believed to be about 82ft long, the Hwasong-17 is the North’s longest-range weapon and, by some estimates, the world’s biggest road-mobile ballistic missile system.

Its size suggests the missile is meant to carry multiple nuclear warheads, given the North already has single-warhead ICBMs that could also hit most of the US.

An anti-Pyongyang rally in Seoul
Protesters stage a rally denouncing North Korea’s missile launch near the US Embassy in Seoul, South Korea (AP)

US-led diplomacy aimed at convincing North Korea to denuclearise in return for economic and political benefits largely has stalled since 2019.

The Biden administration has urged North Korea to return to talks without any preconditions, but Pyongyang has responded that Washington must drop its hostility first and has taken steps to expand its weapons arsenals.

Some experts say Mr Kim could soon conduct another ICBM launch, a launch of a satellite-carrying rocket or a test of a nuclear device as he works to perfect his weapons technology, dial up pressure on the United States and secure stronger internal royalty.

On Monday, South Korea reiterated a previous assessment that there are signs that North Korea is restoring previously demolished tunnels at its underground nuclear testing site.

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

The Hwasong-17 test was the North’s most serious weapons launch since it tested a previously developed ICBM in November 2017. Its last nuclear test, its sixth overall, was in September 2017.