Leader Kim Jong Un has vowed to ramp up his country's naval capacities, and presided over the April launch of the country's first 5,000-ton destroyer-class naval ship, the Choe Hyon.

South Korea's military has said the ship could have been developed with Russian help, possibly in exchange for deploying thousands of troops to help Moscow fight in Ukraine.

Kim also presided over the botched launch of the destroyer Kang Kon in May, which was subsequently repaired and set afloat in June.

Workers at the Nampho Shipyard pledged Monday at a rally to complete the new warship by October 10 next year, according to Pyongyang's official Korean Central News Agency.

The date marks the anniversary of the founding of the ruling Workers' Party of Korea.

The North will now construct the "Choe Hyon-class Destroyer No. 3" which it described as "a powerful warship of our own type".

The Nampho dockyard manager urged workers to meet the construction deadline to uphold the party's "plan for building a powerful army" and "to firmly defend the inviolable maritime sovereignty and national interests," KCNA said.

South Korea's new president, Lee Jae-myung, elected last month in a snap election, has promised a more dovish approach towards Pyongyang, compared with that of his hawkish impeached predecessor Yoon Suk Yeol.

The Lee administration has halted loudspeaker propaganda broadcasts along the border, which Seoul began last year following a barrage of trash-filled balloons flown southward by Pyongyang.

Seemingly in response, North Korea also ended its own propaganda broadcasts which had relayed strange and eerie noises into the South.