North Korean leader Kim Jong-un has pledged to make his hermit kingdom "the world's strongest nuclear power" as he hailed the scientists and workers behind the recent long-range missile launch.

Delivering a lecture at the national defence conference in the North Korean capital Pyongyang on Wednesday, 13 December, Kim – the third-generation dictator of the rogue nation – heralded the recent missile launch as a "great historic victory" for the country.

"I [Kim] solemnly declare that the development of new strategic weapon systems, including A-bomb, H-bomb and ICBM Hwasong-15... completing the state nuclear force, serves as a great historic victory of our party and people of the country achieved it by the death-defying struggle at the cost of high price," said Kim, according to a report by the Korean Central News Agency (KCNA).

Kim had pledged his impoverished nation will march towards becoming "the world's strongest nuclear power and military power" in the coming future as he outlined long-term objectives for North Korean scientists and the defence industry.

"He expressed belief that the scientists of the national defence industry and workers of munitions would bolster up the nuclear force in quality and quantity, manufacture more latest weapons and equipment of Korean style and thus fulfil their honourable mission and duty," he added.

Pyongyang has been racing towards developing a long-range missile equipped with a nuclear warhead which would be capable of reaching the US mainland. Though the country claims to already possess that ability, outside experts are sceptical. However, they insist the Kim regime is rapidly improving its weapons programmes.

In 2017, the North has fired off several ballistic missiles and conducted a nuclear detonation in September, defying international regulations. Pyongyang's latest missile, Hwasong-15 – which was test-fired on 29 November, is widely believed to have the strike radius to target any part of the US mainland.

Kim Jong-un
Some of the photos appear to show the reclusive nation's self-proclaimed supreme leader Kim Jong-un celebrating the successful launch of Hwasong-15 KCNA/Reuters