The North also vowed "stern punishment" against the United States, Japan and other countries over UN Security Council sanctions against the reclusive regime following the October 9 nuclear test.
"The Japanese militarists and other forces favouring the U.S. imperialists' moves should stop running amuck, well aware that they will never escape a stern punishment by the revolutionary armed forces of the DPRK (North Korea) should they go reckless under the signboard of the UN Security Council 'resolution'," the official North Korean news agency KCNA said.
"...if the US imperialists persist in their reckless provocations, this will be nothing but a suicidal act of precipitating their miserable end," KCNA quoted Choe Thae Bok, central committee secretary of the Workers' Party of Korea, as saying.
North Korea, also through KCNA, has previously described the UN sanctions as tantamount to a "declaration of war" and warned it would strike with "merciless blows" against any countries that impinged on its sovereignty.
Friday's warning came just hours after US Secretary of State Condoleezza Rice said she was convinced that Beijing was committed to enforcing the sanctions against its ally North Korea.
But she shot down hopes that a meeting this week between senior Chinese officials and North Korean leader Kim Jong-Il would produce a quick breakthrough in the crisis.
The UN Security Council passed a resolution imposing strong sanctions against the North aimed at curbing Pyongyang's nuclear and other weapons of mass destruction programmes in the wake of test.
Rice, who met Friday with Chinese President Hu Jintao and other leaders, said they were determined to ensure no illicit materials crossed China's long land border with North Korea -- a major conduit for North Korean trade.
Tight controls on cargo flows across the border are seen as critical to enforcement of the UN sanctions.
China had been very reluctant to clamp trade sanctions on North Korea for fear of weakening the Stalinist regime's already faltering economy.
KCNA on Friday did not mention China in its dispatch nor whether the regime would conduct a second nuclear test. A South Korean report Friday, quoting an unidentified diplomatic source, said Kim told the visiting Chinese delegation this week that it would not carry out a second test.
KCNA described the October 9 test, the country's first, as successful and hailed the scientists responsible as heroes. It said North Korea was forced to develop a nuclear programme in response to US threats, and to maintain peace on the Korean peninsula and in northeast Asia.
"The recent nuclear test was a quite just decision to defend the supreme interests of the state and the security of the nation from the U.S. imperialists' threat of aggression, avert a new war and defend peace and stability on the Korean Peninsula," secretary Choe Thae Bok said.

Copyright AFP (Agence France-Presse), 2006