State news agency KCNA said Kim, who came to power in December 2011 after the death of his father, visited the same artillery unit that launched a deadly attack on South Korea's Yeonpyeong island near the western sea border two years ago.
Pyongyang, impoverished and isolated, has periodically used the term "sacred war" to counter what it sees as a threat from the South and its key ally the US.
It has branded this month's military drills "an all-out war rehearsal" for an invasion of the North.
Seoul and Washington say the drill, which will mobilise more than 85,000 servicemen, including some 30,000 US troops, is only for defensive purposes.
