North Korea on Tuesday marks five years since leader Kim Jong Un declared the country's nuclear force was complete, following the first launch in November 2017 of the Hwasong-15 intercontinental ballistic missile. Pyongyang claimed that it had the ability to strike the US mainland.

Earlier this month, the North launched a new and larger model of ICBM, called the Hwasong-17, which experts say could put the whole of the US within its range.

On Sunday, Pyongyang emphasized that it succeeded in launching "the world's most powerful absolute weapon" in a final test.

Kim and his daughter recently posed for photos with scientists involved in the Hwasong-17 project.

The leader also promoted military officials and gave a 22-wheel mobile launching pad the title of "DPRK Hero."

On Tuesday, Pyongyang is expected to highlight the recent launch of the Hwasong-17, in an apparent attempt to beef up Kim's authority at home and to boost the morale of the North Korean people.

State-run media quoted scientists in charge of weapons development as saying they are determined to continue producing state-of-the-art military equipment.