Kim underscored the need to concentrate on readiness in a recent visit to a Korea People's Army Unit, South Korea's Yonhap News Agency reported Monday.
Word of the visit carried by North Korea's official news agency did not reveal a location but said it was Kim's sixth meeting with the commander of a Korea People's Army unit this month.
"No force in the world can match the strength of this great invincible army firmly armed with the spirit of devotedly defending their leader," Kim was quoted as telling the unit.
Communist North Korea has more than 1.1 million troops facing a South Korean army of 600,000.
The two Koreas are still technically at war since the Korean War ended with only an armistice and not a peace treaty.