North Korea's ruling Workers' Party has again chosen Kim Jong Un as its general secretary, state media reported.

The announcement by the rubber-stamp party congress on Sunday comes as little surprise, given that the Kim family has ruled the dictatorship since the late 1940s.

State-run KCNA said that under Kim's leadership, North Korea "radically improved" its "war deterrence", "with the nuclear forces as its pivot".

Despite long-standing international sanctions, North Korea has continued to build its nuclear capabilities, regularly testing banned intercontinental missiles. But the regime's secrecy makes it harder to assess how much progress the military has made.

Kim, who took over control of the regime after his father's death in 2011, has invested heavily in the nuclear weapons programme, turning Pyongyang into a far bigger challenge for the West, and especially the US.

He is expected to announce the next phase of the country's weapons programme during the congress, which is now in its fourth day. Before it started, North Korea unveiled what it said was a range of nuclear-capable rocket launchers.

The congress, held once every five years over the last decade, began on 19 February.

With some 5,000 party members in attendance, according to KCNA, it offers a rare glimpse into the structure of political power in North Korea, which remains quite opaque even to the keenest watchers.

The meetings are considered the most important political event and provide insight into the country's priorities, from foreign policy to its nuclear ambitions.

While Kim has remained at the top of North Korean leadership, the party congress' presidium, or executive committee, has been reshuffled since the last meeting in 2021. More than half of its 39 members have been replaced, according to state media.

In his opening speech last week, Kim vowed to boost the country's economy and people's standard of living, describing it as "heavy and urgent historic tasks".

And all eyes are on whether Kim's daughter, Ju Ae, will make an appearance.

Earlier this month, South Korea's spy agency said that Kim had chosen Ju Ae as his heir. Kim Ju Ae, believed to be 13 years old, has become an increasingly prominent figure at official events - inspecting missiles and attending Beijing's military parade with her father.