North Korean leader Kim Jong-un has inspected a front-line military unit on an island just north of the western sea border with South Korea, Pyongyang's official news agency said Monday, in his third trip to military installations this month.

Kim "inspected the Changrin Islet defense detachment on the western front," according to the Korean Central News Agency in English. The islet lies just north of the Northern Limit Line, a de facto maritime border with South Korea, which was the site of bloody naval skirmishes between the two Koreas in the past.

"He stressed the need for the units and subunits at all levels of the People's Army to make technical arrangements and technical management in a responsible manner for full preparations for regular mobilization of the weapons and combat and technical apparatuses," the KCNA said.

Kim ordered soldiers "to set up a well-knit system" to ensure "full readiness for carrying out a combat mission any moment," it added.

The KCNA said that Kim's late father and former leader, Kim Jong-il, also toured the islet and the front unit decades ago.

"Seeing the monument to the field guidance of Chairman Kim Jong-il which was built to hand down the immortal exploits of Kim Jong-il who left the legendary traces of army commanding in the islet 45 years ago, the Supreme Leader was lost in deep thought about him," the KCNA said.

In a separate report, Pyongyang's state media reported that leader Kim also visited a "women's company under Unit 5492 of the Korean People's Army" stationed "at the remote seaside on the southwestern front, a unit his late father also visited long ago."

"Conducted by the company commander and company political instructor, he made round of the monument to the field guidance of Chairman Kim Jong-il," it said. "He looked at the moment for a long while, being lost deep in thought about Kim Jong-il."

The latest "field guidance" marked his third reported visit to military installations this month. He attended an air show on Nov. 16 and supervised an airborne landing training two days later, underlining the need to improve war readiness.

It came amid North Korea's ramped-up demand for Washington to drop its "hostile policy" toward its regime and come up with an acceptable proposal before its self-imposed end-of-year deadline.

Nuclear negotiations have been stalled since the second summit between Kim and US President Donald Trump broke down in February as they failed to find common ground over how to match Pyongyang's denuclearization steps and Washington's sanctions relief.

The two counties held working-level talks last month for the first time since the summit breakdown but failed to produce any tangible progress. (Yonhap)