US and South Korea started on Monday military drills south of the border, saying the exercises were routine and defensive in nature, but Pyongyang calls them a rehearsal for a nuclear attack.
Pyongyang threatened on Tuesday a military response to ongoing joint US-South Korean war games, as Seoul’s leader called for talks with the neighbor to in order to defuse tensions on the Korean Peninsula.
US and South Korea started on Monday military drills south of the border, saying the exercises were routine and defensive in nature, but Pyongyang calls them a rehearsal for a nuclear attack.
The North's foreign ministry said "physical counter-action" by its armed forces was "inevitable" for what it called "self-defense", in a statement carried by the communist state's official news agency.
Pyongyang said it had pursued dialogue but the opportunity was fading.
"The US should be wholly accountable for all the consequences to be entailed by its military provocations. The DPRK is ready for both dialogue and confrontation," it said.
The comments were the latest in a series blasting the exercises. On Sunday the North's military vowed to turn Seoul into a "sea of flames" in the event of any provocation.
The army has also threatened to open fire on a tourist site at Imjingak in the South, to halt future launches of propaganda leaflets across the heavily fortified border.
Meanwhile, South Korea's President Lee Myung-Bak said his country "is ready to engage in dialogue with the North anytime with an open mind".
Lee, in a speech marking a 1919 campaign for independence against Japanese colonizers, said it was time to sweep away the "legacy of the Cold War" and for the North to join a new wave of peace and prosperity in Northeast Asia.
"There is no reason for South Korea not to help our compatriots in the North when it is helping many other countries," Lee said.
"The North should step forward for serious dialogue and cooperation and refrain from developing nuclear weapons and missiles."
But Lee also repeated calls for Pyongyang to take "responsible measures" on past provocations.
Relations between the two neighbors witnessed this year high tensions. Last March, a South Korean ship drawn with the loss of about 46 sailors onboard. Seoul blamed Pyongyang for the attack, saying it torpedoed the ship. However the North denied any involvement.
In another incident, the North shelled a Southern island in November 23, killing two soldiers and two civilians.
