"Whatever the scale and mode, the joint military exercises are of aggressive nature as they are a war rehearsal and preliminary nuclear war exercise for further rounding off the preparations for putting into practice the operational plan with the preemptive strike at us as the gist," Kim said, as quoted by the Korean Central News Agency.
Pyongyang will accelerate the strengthening of its defense capacities in response, the North Korean leader's sister went on.
"We will put more spur to further increasing the deterrent of absolute capacity to cope with the ever-growing military threats from the U.S., i.e. the national defence capabilities and powerful preemptive strike for rapidly countering any military actions against us," Kim noted.
North Korea will counter the US on the "principle of power for power and goodwill for goodwill," Kim added, arguing that Washington must withdraw its troops from South Korea to set peace on the entire Korean peninsula.
On Monday, media reported that this week Washington and Seoul will conduct preparations for the joint computer-simulated military exercises that will take place from August 16-26 without any real maneuvers.