North Korean leader Kim Jong Un has ordered the “exponential” expansion of his country’s nuclear arsenal, the development of a more powerful intercontinental ballistic missile and the launch of its first spy satellite, state media reported on Sunday.

The announcement came after he entered 2023 with another weapons firing following a record number of testing activities last year.

Mr Kim’s moves are in line with the broad direction of his nuclear weapons development programme as he has repeatedly vowed to boost both the quality and quantity of his arsenal to cope with what he calls US hostility.

Some experts say his push to produce more nuclear arms and new weapons systems reflects his hopes of solidifying his future negotiating power as he heads into prolonged tensions with the US and its allies.

“They are now keen on isolating and stifling (North Korea), unprecedented in human history,” Mr Kim said at a recent ruling party meeting, according to the official Korean Central News Agency.

“The prevailing situation calls for making redoubled efforts to overwhelmingly beef up the military muscle.”

Mr Kim accused South Korea of being “hell-bent on imprudent and dangerous arms build-up” and openly trumpeting its preparations for war with North Korea.

That, he said, highlights the need to mass-produce battlefield tactical nuclear weapons and push for “an exponential increase of the country’s nuclear arsenal”, KCNA reported.

Mr Kim also set out plans to develop another ICBM system “whose main mission is quick nuclear counterstrike”, KCNA said. It said the leader accused the US of frequently deploying nuclear strike means in South Korea and pushing to establish a Nato-like regional military bloc.

Mr Kim said North Korea will also launch its first military reconnaissance satellite “at the earliest date possible”, saying related preparations are in their final stages.

Tactical nuclear weapons and a military reconnaissance satellite are on Mr Kim’s long wish list of new weaponry. Other weapons he wants include a multi-warhead missile, a more agile solid-fuelled ICBM, an underwater-launched nuclear missile and a hypersonic weapon.

Soo Kim, a security analyst at the California-based Rand Corporation, said: “Kim’s comments from the party meeting reads like an ambitious – but perhaps achievable – New Year’s Resolution list.

“It’s ambitious in that Kim consciously chose to spell out what he hopes to accomplish as we head into 2023, but it also suggests a dose of confidence on Kim’s part.”

Last month, North Korea claimed to have performed key tests needed for the development of a new strategic weapon, a likely reference to a solid-fuelled ICBM, and a spy satellite.

Mr Kim’s identification of South Korea as an enemy and the mentioning of hostile US and South Korean policies is “a reliable pretext for the regime to produce more missiles and weapons to solidify Kim’s negotiating position and concretise North Korea’s status as a nuclear weapons power”, Ms Soo said.

Some observers say North Korea wants to become a legitimate nuclear power state as a way to win the lifting of UN and other international sanctions and force the end of the regular US-South Korean military drills that the North views as an invasion rehearsal.

Ankit Panda, an expert with the Carnegie Endowment for International Peace, said: “It was during his 2018 New Year’s speech that (Kim) first ordered the mass production of warheads and ballistic missiles, and he’s doubling down on that quantitative expansion goal in the coming year.”

Mr Panda said the reference to a new ICBM appears to concern a solid-propellant system, saying “we should expect to see larger, solid propellant missiles tested soon”.

He said the satellite launch should take place in April. North Korea typically marks April 15, the birth date of Kim’s late father and state founder, Kim Il Sung, with great fanfare and state-organised celebrations.

Outside fears about North Korea’s nuclear programme have grown since the North last year approved a new law that authorised the pre-emptive use of nuclear weapons in a broad range of situations and openly threatened to use its nuclear weapons first.

During his speech at the party meeting, Mr Kim reiterated that threat.

KCNA said: “(Kim’s report) made clear that our nuclear force considers it as the first mission to deter war and safeguard peace and stability. However, if it fails to deter, it will carry out the second mission, which will not be for defence.”

The North’s increasing nuclear threats have prompted the US and South Korea to expand their military exercises and strengthen a trilateral security co-operation involving Japan.

The US military has warned that any nuclear attack by North Korea against the United States or its allies and partners “will result in the end of that regime”.

Earlier on Sunday, South Korea’s military detected a missile launch from the North’s capital region.

The Joint Chiefs of Staff said in a statement the missile travelled about 250 miles (400km) before falling into the water between the Korean Peninsula and Japan.

It called the launch “a grave provocation” that hurts peace and security on the Korean Peninsula and around the world. It said South Korea maintains a readiness to overwhelmingly deal with any provocations.

The US Indo-Pacific Command said in a statement that the US commitments to defend South Korea and Japan “remain ironclad”.

North Korea test-fired more than 70 missiles last year, including the three short-range ballistic missiles detected by South Korea on Saturday.

The North’s testing spree indicates the country has been emboldened by its advancing nuclear programme, though whether the country has functioning nuclear missiles remains a source of outside debate.

North Korea’s state media confirmed on Sunday that the country carried out the test-firings of its super-large multiple rocket launcher to test the weapon’s capability.

KCNA said three shells fired from the launcher on Saturday accurately hit an island target off the country’s eastern coast. It said North Korea fired another shell from the launcher towards its eastern waters on Sunday.

Mr Kim said the rocket launcher puts all of South Korea within striking distance and is capable of carrying a tactical nuclear warhead, according to KCNA.

Outside experts categorise weapons fired from the launcher as ballistic missiles because of their trajectories, ranges and other characteristics.

Leif-Eric Easley, a professor at Ewha University in Seoul, said: “Its recent missile launches were not technically impressive. Instead, the high volume of tests at unusual times and from various locations demonstrate that North Korea could launch different types of attack, any time, and from many directions.”

Animosity between the rival Koreas has deepened further since early last week, when South Korea accused North Korea of flying drones across the countries’ heavily fortified border for the first time in five years and responded by sending its own drones toward the North.