New Joint Chiefs of Staff Chairman Kim Seung-kyum speaks during a change of command ceremony at the JCS headquarters in Seoul, July 5. Joint Press Corps

The new head of South Korea's Joint Chiefs of Staff (JCS) on Wednesday presided over his first meeting with major military commanders since taking office earlier this month, a military source said.

During the meeting, Gen. Kim Seung-kyum ordered commanders to establish a firm readiness posture amid a grave security situation due to recent provocations from North Korea and signs that the recalcitrant regime is preparing for a nuclear test, according to the source.

Kim also stressed improving the readiness posture and capabilities in order to respond firmly and punish any provocation.

In his inauguration speech on July 5, Kim warned that North Korea's provocations will be met with "unsparing retaliation." (Yonhap)