Saturday's drill, designed to "sternly respond" to potential missile launches by the North, saw two US bombers destroy "enemy" missile batteries and South Korean jets mount precision strikes against underground command posts.

The North's state-run Rodong newspaper accused Washington and Seoul of ratcheting up tensions with the drill, in an editorial titled "Don't play with fire on a powder keg."

"The US, with its dangerous military provocation, is pushing the risk of a nuclear war on the peninsula to a tipping point," it said, describing the peninsula as the "world's biggest tinderbox."