South Korean military authorities are closely monitoring movement in North Korea following intelligence reports the North relocated an intermediate-range missile to its east coast.

A military official says there is a possibility that Pyongyang could launch the missile this month, adding South Korean and U.S. intelligence officials are monitoring the North’s missile base around the clock.

The source said since North Korea threatened to nullify the Korean War armistice early last month, South Korea has beefed up its front line security posture and maintained a high level of readiness that will allow the mobilization of all commanders within an hour.