North Korean leader Kim Jong Un oversaw the delivery of 250 ballistic missile launchers to frontline units along the southern border, describing the weapons as a "powerful treasured sword" for defending sovereignty, state media reported on Monday.

The "ceremony for transferring 250 new-type tactical ballistic missile launchers... to the frontier military units" occurred in Pyongyang on Sunday, according to the official Korean Central News Agency (KCNA), with Kim presiding over the event.

Kim referred to the missile launchers as an "up-to-date tactical attack weapon" and claimed he "personally designed" them.

Relations between North and South Korea have deteriorated significantly, with the North increasing weapons testing and sending balloons filled with trash over the border.

In response, South Korea has resumed propaganda broadcasts along the border, suspended a military agreement aimed at reducing tensions, and restarted live-fire drills near the border.

This year, Pyongyang declared South Korea its "principal enemy," disbanded agencies focused on reunification and outreach, and threatened war over "even 0.001 mm" of territorial infringement.

Kim stated in his speech that showcasing the new weapons amidst the country's recovery from flood damage demonstrated the Party's "firm will to push ahead with the bolstering of defense capabilities," according to KCNA.

Heavy rainfall hit the nuclear-armed country's northern regions in late July, with a South Korean media report suggesting up to 1,500 people may have died.

Kim dismissed these reports as a "smear campaign to bring disgrace upon us and tarnish" North Korea's image.

North Korea claimed there were no casualties in the Sinuiju area, the region it identified as having suffered the "greatest flood damage." The North also stated that its Air Force rescued over 5,000 people, with approximately 4,200 saved by helicopter "within a few hours."