North Korean leader Kim Jong-un inspected a hydrogen bomb being loaded into a new intercontinental ballistic missile (ICBM) after the country claimed that it has succeeded in making a “more developed nuke”, state-media reported on Sunday.

Kim made the inspection during a visit to the country’s Nuclear Weapons Institute, according to the Korean Central News Agency (KCNA).

However the agency did not disclose when the visit was made, reports CNN.

“The hydrogen bomb, the explosive power of which is adjustable from 10 kilotonne to hundreds kilotonne, is a multi-functional thermonuclear nuke with great destructive power which can be detonated even at high altitudes for super-powerful EMP (electromagnetic pulse) attack on strategic goals,” KCNA reported.

Electromagnetic pulse is an intense wave of electrical energy generated by the detonation of a nuclear weapon.

“Scientists further upgraded its technical performance at a higher ultra-modern level on the basis of precious successes made in the first hydrogen bomb test,” the agency added.

In January 2016, North Korea conducted its fourth nuclear test, which Pyongyang claimed to be a successful trial of a hydrogen bomb, reports Yonhap News Agency.

North Korea has carried out five nuclear tests since 2006, including two last year.

Pyongyang boasted about its nuclear missile programme in Sunday’s report, saying it has the know-how and materials to make as many weapons as it wants.

“All components of the hydrogen bomb were 100 per cent homemade and all the processes ranging from the production of weapons-grade nuclear materials to precision processing of components and their assembling were indigenously developed, thus enabling the country to produce powerful nuclear weapons as many as it wants,” CNN quoted the KCNA report as saying.

The Kim Jong-un regime has also unveiled photos indicating that it may be developing a new submarine-launched, solid-fuel missile, called the Pukguksong-3 and a Hwasong-13 ICBM.

Sunday’s development comes amid heightened tensions after North Korea tested two ICBMs in July.

Analysts said the ICBM tests could put much of the US mainland within range, including Los Angeles and Chicago.

US President Donald Trump earlier warned North Korea of “fire and fury”. In response, Pyongyang threatened to fire a salvo of missiles into waters near the American territory of Guam though it held off on the plan later.