South Korea's military is separately searching for Korean War remains at the heavily armed inter-Korean border after North Korea ignored its calls to carry out a previously planned joint search.

Seoul's Defense Ministry said Monday that South Korean soldiers will remove mines and proceed with excavation work at an area south of the military demarcation line that bisects the rivals.

The joint recovery of war remains was one of many peace agreements reached between the Koreas last year as they took steps to improve bilateral relations amid the larger nuclear negotiations between North Korea and the United States.

But North Korea has shown less enthusiasm about upholding inter-Korean agreements following the collapse of February's high-stakes summit between leader Kim Jong Un and U.S. President Donald Trump.