North Korean leader Kim Jong Un convened all military commanding officers for a special meeting on Sunday where he demanded improvements to training systems and called for turning the inter-Korean border into an “impregnable fortress,” according to state media.

The Korean Central News Agency (KCNA) reported Monday that Kim ordered a new “structural measure for updating our army” both organizationally and technically. It described the meeting as involving “the commanding officers of the divisions and brigades of the entire army.”

He repeatedly stressed the issue of “practical training,” saying North Korea’s military must keep up with “changing aspects of