North Korean leader Kim Jong-un pledged to strengthen his country’s nuclear arsenal in his closing address to a top ruling party meeting, state media reported on January 13, days before Joe Biden takes office as US president.

Kim is looking to grab the attention of the incoming Biden administration, analysts say, with his country more isolated than ever after closing its borders to protect itself against the coronavirus pandemic.

A nuclear summit between Kim and outgoing US President Donald Trump in Hanoi in February 2019 broke down over sanctions relief and what Pyongyang would be willing to give up in return.

“While strengthening our nuclear war deterrent, we need to do everything in order to build the most powerful military,” the official Korean Central News Agency (KCNA) cited him as telling the Workers’ Party congress.

Earlier in the eight-day congress – twice as long as the previous meeting in 2016 – Kim called the US “the fundamental obstacle to the development of our revolution and our foremost principal enemy”.

“The real intention of its policy toward the DPRK will never change, whoever comes into power,” he said using North Korea’s official acronym, without mentioning Biden by name.

The North had completed plans for a nuclear-powered submarine, he said – which would be a strategic game-changer – and offered a shopping list of weapons goals, including hypersonic gliding warheads, military reconnaissance satellites and solid-fuel intercontinental ballistic missiles (ICBMs).

The North’s weapons programmes have made rapid progress under Kim, including by far its most powerful nuclear blast to date and missiles capable of reaching the entire continental US, at a cost of increasingly stringent international sanctions.

At a military parade in October, it showed off a huge new ICBM that analysts said was the largest road-mobile, liquid-fuelled missile in the world.

Kim and Trump had a tumultuous relationship, first engaging in mutual insults and threats of war, before an extraordinary diplomatic bromance featuring headline-grabbing summits and declarations of love by the US president.

The change of leadership in Washington presents a challenge for Pyongyang – Biden characterised Kim as a “thug” during the presidential debates, while the North has previously called Biden a “rabid dog” that “must be beaten to death with a stick”.

The congress is the top ruling party gathering, a grand political set-piece that reinforces the regime’s authority and can serve as a platform for announcements of policy shifts or elite personnel changes.

At the gathering, Kim was named the party General Secretary, a title previously reserved for his father and predecessor Kim Jong-il, in what analysts said was a move to reinforce his authority.

The North’s economy is struggling in the face of its self-imposed coronavirus blockade, mismanagement and sanctions, and Kim repeatedly admitted at the meeting that mistakes had been made.

“Almost all sectors fell a long way short of the set objectives” in the country’s previous economic plan, he said earlier.