Escalating military tensions on the divided Korean peninsula took an increasingly personal turn Friday, with the leaders of North and South each threatening the other's destruction.

For North Korean leader Kim Jong-Un that meant overseeing a long-range artillery drill, simulating a strike on the offices and official residence of his South Korean counterpart, Park Geun-Hye.

Park, meanwhile, countered by accusing Kim of leading his country down a "path of self destruction" and suggesting it was time for regime change in Pyongyang.

Tensions between the two Koreas have been rising since North Korea carried out its fourth nuclear test in January, and a satellite rocket launch a month later that was widely seen as a disguised ballistic missile test.

Pyongyang has upped the rhetorical ante in recent weeks, with near daily threats of nuclear and conventional strikes against the South and the US mainland in response to large-scale South-US war games.

On Wednesday, it warned of a "miserable end" facing Park Geun-Hye, with its artillery units standing ready to turn the presidential Blue House in Seoul into a "sea of flames and ashes".

- 'Lightning' strikes -

According to a report by the North's official KCNA news agency on Friday, Kim took that warning a step further by ordering and personally monitoring a live-fire exercise involving the same target.

"Artillery shells flew like lightning and intensely and fiercely struck targets simulating Cheong Wa Dae and rebel governing bodies in Seoul," the North's official KCNA news agency said.

Cheong Wa Dae is the Korean name for the Blue House.

According to KCNA, it was the largest drill of its type ever conducted, involving "hundreds of different types" of long-range artillery.

"If the enemies challenge us... our artillery forces' merciless retaliating blow will turn Seoul into rubble and ashes," Kim was quoted as saying.

The North's ruling party newspaper, Rodong Sinmun, published around 40 colour photos of the drill in its Friday edition, showing Kim watching through binoculars as multiple batteries of heavy-calibre artillery units and missile rocket launchers pounded an offshore island from a beach.

South Korea's Yonhap news agency cited military sources as saying the exercise was held Thursday near the eastern port city of Wonsan.

The North always reacts strongly to the annual South-US military exercises, which it sees as provocative rehearsals for invasion.

- 'Decapitation' drill -

Its protests have been especially vocal this year, because of the first-time inclusion in the ostensibly defensive drills of a special operation that envisages strikes to "decapitate" North Korea's top leadership.

The KCNA report made it clear that the artillery drill was a direct response to that operation by "the gangster US and Park Geun-Hye forces".

Speaking later in the day at a memorial to mark bitter North-South clashes on the disputed Yellow Sea, president Park said the South would "not be shaken one bit" by threats.

"Reckless provocations will only become a path to self-destruction for the North Korean regime," she said, adding that the international community was united in its opposition to Pyongyang's nuclear ambitions.

"Now we have the opportunity to bring about change in the North Korean regime," Park said.

The North's fourth nuclear test in January saw the UN Security Council -- backed by Pyongyang's main ally China -- impose its harshest sanctions to date over the North's nuclear weapons programme.

The North responded defiantly, claiming a series of key breakthroughs in its development of a long-range nuclear strike capability, and conducting its first test firing in two years of a medium-range ballistic missile.