South Korea plans to install unmanned vigilance equipment at major military posts to complement surveillance soldiers in line with an expected reduction in the troop numbers, the state defense acquisition agency said Monday.

The military will gradually put up high-definition security cameras and attach infiltration detection equipment to barbed wires at major units from this year until 2024, according to the Defense Acquisition Program Administration.

In the first phase, the agency will spend 40 billion won ($34 million) on equipping the unmanned surveillance system at 12 units through next year. Investment sizes for the second and third phases will be decided later, a DAPA spokesman said.

(Yonhap)Last year, the military placed vigilance and detection equipment along the 249 kilometer-long (155 mile-long) barbed wire fence on the heavily fortified border with North Korea.

The move comes amid expectations that the number of soldiers will fall to 522,000 in 2022 from the current 620,000.

South Korea's total fertility rate -- the average number of children a woman bears in her lifetime -- stood at 1.24 in 2015, much lower than the replacement level of 2.1 that would keep South Korea's population of 51 million stable.

All able-bodied South Korean men must carry out compulsory military service for about two years in a country facing North Korea across the heavily fortified border. (Yonhap)