North Korea is formally abolishing key government agencies charged with promoting cooperation and reunification with the South, state media said on Tuesday, as leader Kim Jong Un called for constitutional changes allowing Pyongyang to ‘occupy’ Seoul in war.

Inter-Korean relations have sharply deteriorated in recent months, with Pyongyang’s November spy satellite launch prompting Seoul to partially suspend a 2018 military agreement aimed at defusing tensions.

Pyongyang’s decision was announced by the North’s rubber-stamp parliament, the Korean Central News Agency said, and is part of a string of recent measures, including live-fire artillery drills and missile launches, that have escalated tensions.

In a speech delivered at the Supreme People’s Assembly, Kim called for drawing up new legal measures to define South Korea as ‘the most hostile country’, KCNA reported.

‘In the event of war on the Korean Peninsula, I think it is also important to reflect on the issue of completely occupying, suppressing, and reclaiming the Republic of Korea and incorporating it into the territory of our Republic,’ Kim said.

The decision comes shortly after Kim labelled South Korea the ‘principal enemy’ and stated that continuing to seek reconciliation was a ‘mistake’.

In their constitutions, both North and South Korea claim sovereignty over the whole of the peninsula.

The Democratic People’s Republic of Korea and Republic of Korea — the North and South’s official names — were founded 75 years ago but still technically regard each other as illegal entities.

Until now, what passed for diplomatic relations was handled by Seoul’s Unification Ministry and Pyongyang’s Committee for the Peaceful Reunification — one of the agencies that the Supreme People’s Assembly has now declared abolished.

‘The two most hostile states, which are at war, are now in acute confrontation on the Korean peninsula,’ the decision adopted by the assembly said, according to KCNA.

‘The reunification of Korea can never be achieved with the Republic of Korea,’ it added.

At Pyongyang’s year-end policy meetings, Kim threatened a nuclear attack on the South and called for a build-up of his country’s military arsenal ahead of armed conflict he warned could ‘break out any time’.

On Sunday, the North launched a solid-fuel hypersonic missile, Pyongyang’s first known weapons test this year and its first-ever test of a solid-fuel hypersonic intermediate-range ballistic missile (IRBM).

The launch came just days after Pyongyang staged live-fire exercises near the country’s tense maritime border with South Korea, which prompted counter-exercises and evacuation orders for some border islands belonging to the South.

Kim also successfully put a spy satellite into orbit late last year, after receiving what Seoul said was Russian help, in exchange for arms transfers for Moscow’s war in Ukraine.

Traditional allies Russia and North Korea have boosted ties recently, with Kim making a rare overseas trip to see President Vladimir Putin in Russia’s far east in September.

Top Russian officials, including Moscow’s defence and foreign ministers, also visited North Korea last year, with the flurry of trips both ways fanning concern among Kyiv’s allies over the possibility of a potential arms deal.

On Monday, a North Korean government delegation headed by Foreign Minister Choe Son Hui arrived in Moscow for an official visit, KCNA reported.