The North’s National Defence Commission (NDC) described the exercise as “unpardonable war hysteria” and said its army and people would “foil” the US and South Korean moves with “a sacred war of our own style”.
The threat is the latest instance of Pyongyang taking a hostile tone towards Seoul since Kim Jong-un, the youngest son of the late leader Kim Jong-il, took over following the death of his father in December.
The North vowed “merciless retaliatory strikes” if any shells landed in waters claimed by Pyongyang during a live-fire artillery exercise near the disputed Yellow Sea border.
But in the event it took no military action in response to the drill.
The United States and South Korea are to mount two major annual joint military exercises.