North Korea is poised to launch a short-range missile from its east coast, military authorities here believe.

"We've spotted signs that the North is preparing to launch what is presumed to be a surface-to-ship missile from near Wonsan on the east coast," a military source here said Wednesday. "It's probably a routine exercise or test-launch, but we're checking if it's a show of force" amid resurgent cross-border tension.

The missile could be a KN-01-class surface-to-ship cruise missile with a range of more than 120 km.

The North has continued to improve the performance of its surface-to-ship missiles to defend itself against South Korean and U.S. amphibious ships designed to support landing operations and South Korean Navy boats operating near the Northern Limit Line, the de-facto maritime border which runs close to its coast.

Pyongyang is reportedly developing a new surface-to-ship ballistic missile that cannot be intercepted by the South Korean Navy with its current weapons because it is much faster than the cruise missile.

Military authorities here failed to disclose that on June 26, a day before President Park Geun-hye visited China, the North launched four short-range missiles from a new 300-mm multiple rocket launcher from the east coast.

