Tensions on the Korean peninsula have increased since the North last month launched a spy satellite, prompting Seoul to suspend a key clause in a 2018 inter-Korean military accord and Pyongyang in turn to declare it was no longer bound by the pact.
Visiting North Korea's air force command on Thursday to the branch's airmen day, Kim rolled out guidelines to improve the military's combat posture and increase "its capabilities to fight a war to the full," news agency KCNA reported.
"He set forth operational and tactical policies ... so as to counter any military provocation and threat of the enemy immediately and powerfully," KCNA said on Friday.
That stop was followed by a visit to a fighter wing, where pilots staged a demonstration flight, it said.
Photographs released by state media showed Kim and his daughter, both dressed in long leather jackets, watching the show.
Kim praised the air force for being "fully prepared to perfectly carry out their air combat missions under any unfavourable situation," KCNA said.
The United States and its allies have strongly condemned the North's first spy satellite launch as a violation of multiple United Nations Security Council resolutions. But Pyongyang has said it would launch more satellites, calling it an exercise of a right to self-defence.
On Thursday, the US targeted North Korea with fresh sanctions over the satellite launch, designating foreign-based agents it accused of facilitating sanctions evasion. South Korea also announced sanctions on 11 North Koreans.
Reflecting the rising strain, South Korea has suspended tours of the Demilitarised Zone (DMZ) between the two Koreas, a Seoul official said.
Local media reported that North Korean soldiers at the Joint Security Area (JSA) inside the DMZ had started carrying firearms again after the North withdrew from the inter-Korean military deal.
The DMZ tours had restarted last week; they had been halted after a US soldier's unauthorised crossing into North Korea while on a tour in July. Private Travis King was later handed back by the North and returned to the US, where he faces charges.
