North Korea has threatened to cancel the 1953 ceasefire that ended the Korean War, citing a US-led push for punishing UN sanctions over its recent nuclear test and ongoing US-South Korean joint military drills.
The threat came on Tuesday as the United States, with Chinese backing, introduced a draft UN resolution to punish North Korea for its nuclear test on February 12.
Under the new agreement North Korea would face some of the toughest sanctions aimed at reining in Pyongyang's nuclear and ballistic missile programmes and preventing their export to other countries.
The UN resolution, worked out by US Ambassador Susan Rice and China's UN Ambassador Li Baodong over the last three weeks, reflects the growing anger of the UN's most powerful body at North Korea's defiance of three previous sanctions demanding a halt to all nuclear and missile tests.
North Korea, however, remained defiant with a Korean People's Army spokesman threatening to declare the Armistice Agreement "invalid".
"The Democratic People's Republic of Korea will make a strike of justice at any target anytime, as it pleases, without limit, not bound to the Armistice Agreement," Kim Yong-chol said.
In response, Jay Carney, White House spokesman, told reporters that the latest threats will only further isolate North Korea.
"We have urged the North Korean leadership to heed President Obama's call to choose the path of peace and to come into compliance with its international obligations," Carney said.
Pyongyang's recent nuclear test and rocket launches, and the subsequent call for UN punishment, have increased already high animosity between the North and Washington and Seoul.
The US and others worry that North Korea's third nuclear test takes it a big step closer towards its goal of having nuclear-armed missiles that can reach America.
They condemn its nuclear and missile efforts as threats to regional security and a drain on the resources that could go to North Korea's largely destitute people.
North Korea says its nuclear program is a response to US hostility that dates back to the 1950-53 Korean War, which ended with an armistice, not a peace treaty, leaving the Korean Peninsula still technically in a state of war.
North Korean propaganda regularly cites decades-old, Cold War-era American threats as the reason for its nuclear efforts and holds that the North remains at risk of an unprovoked nuclear attack.
Washington and others say brinkmanship is the North's true motive for the nuclear push.
The North's statement called US-South Korean military drills a "dangerous nuclear war targeted at us".