North Korea has boosted surveillance equipment on the west coast near South Korea's northwesternmost islands. The South Korean military believes the new equipment is not only for surveillance but also for offensive purposes.

The fortification comes despite the South Korean Defense Ministry's pledge in a briefing to President Moon Jae-in to "discuss creating a peace zone in the West Sea with the North."

"The North has recently installed surveillance equipment near the northwesternmost islands," a military source here said. "It seems to be part of an overall strategy to improve military capabilities there."

Most of the North's surveillance activities used to rely on the naked eye, but the new equipment can be used from inside bunkers.

In contrast, South Korea's surveillance drone Heron, which used to be deployed in that area, has been grounded since it crashed in February 2018. "We'll be able to resume drone operations next month," a military spokesman said.

