Kim said the danger of an armed confrontation on the Korean peninsula is fast becoming a reality because of hostile manoeuvres by enemies including the US, requiring the country to "sharpen the treasured sword" to protect itself.
"If the enemy opt for military confrontation ... our army should deal a deadly blow to thoroughly annihilate them by mobilising all the toughest means and potentialities without moment's hesitation," KCNA news agency on Monday quoted Kim as saying.
Kim made the comments as he hosted senior military leaders on Sunday at the ruling Workers' Party (WPK) headquarters to congratulate them on accomplishments in 2023, the state news agency said.
North Korea in 2023 tested its largest ballistic missiles and launched its first military reconnaissance satellite, which Kim has called major advances in modernising the country's military.
The call to upgrade the country's military readiness follows the pledge made at the conclusion of a five-day WPK meeting that ended on Saturday to boost its nuclear arsenal, build military drones and launch three new spy satellites in 2024.
The escalation of rhetoric from Kim comes as the US increased drills with South Korea in the past year, deploying more strategic military assets, including a nuclear missile submarine, aircraft carriers and large bombers.
It also comes ahead of a year that will see pivotal elections in both South Korea and the US, which Pyongyang likely sees as an opportunity to increase its leverage by stepping up a campaign of military pressure.
On Monday, South Korean President Yoon Suk Yeol pledged to accelerate work to complete a missile defence system and a system using US extended deterrence to "fundamentally deter any North Korean nuclear and missile threat".
Extended deterrence refers to the strategy of using US military assets including nuclear weapons to deter and, in the event of an attack against an ally, respond.
In separate reports, KCNA said Kim hosted a reception for senior members of the ruling party and attended a late night "grand art performance" celebrating the new year at the May Day stadium in Pyongyang, where senior party members, soldiers and members of the diplomatic corps were present.
The show featured ice skaters, acrobats and choirs, and fireworks lit up the sky at midnight, as the venue filled "with great happiness and boundless excitement of seeing in the New Year with the benevolent father of the great socialist family".
