The powerful sister of North Korean leader Kim Jong Un slammed Seoul Monday for recent military drills near the border, saying the South must be "suicidal" and warning of a "terrible disaster".
After Pyongyang sent multiple barrages of trash-carrying balloons across the border, Seoul last month fully suspended a tension-reducing military deal and resumed live-fire drills on border islands and by the demilitarised zone that divides the Korean Peninsula.
Kim Yo Jong, who is a key regime spokesperson, said this was "an undisguised war game (and) an inexcusable and explicit provocation that aggravates the situation," according to a statement carried by the official Korean Central News Agency.
South Korea's border drills were "suicidal hysteria, for which they will have to sustain terrible disaster," she added.
Kim Yo Jong said it was "clear to everyone... the riskiness of the above-said reckless live ammunition firing drills of the ROK army coming nearer to the border of the DPRK," referring to the South by its official name, the Republic of Korea.
If Seoul's exercises breach the North's sovereignty, Kim Yo Jong warned: "our armed forces will immediately carry out its mission," without giving further details.
Relations between the two Koreas are at one of their lowest points in years, with Pyongyang ramping up weapons testing as it draws ever closer to Russia.
Seoul and Washington have accused Pyongyang of supplying arms to Moscow for use in the war in Ukraine -- which would violate rafts of sanctions on both countries.
Earlier this year, the nuclear-armed North declared Seoul its chief enemy, and has jettisoned agencies designed for outreach and diplomacy with Seoul, while ramping up security along the shared border.
North Korean soldiers have crossed the border three times in recent weeks, likely accidentally Seoul's military says, while they were working to lay mines, clear foliage and build likely anti-tank barriers.
Kim Yo Jong also criticised recent trilateral drills between the United States, South Korea and Japan, saying they were "the height of confrontational hysteria".
"The war drumbeats clearly showed that the US and other hostile forces' rash manoeuvres for military hegemony in the region have crossed the red line," she added.