The North Korean propaganda apparatus is not known for understatements, but Pyongyang on Wednesday upped the ante even by its own standards when it threatened the United States with the "most disastrous final doom on its mainland," warning that "the time of the nightmare" was near, ABC News reported.

In the view of the country's all-powerful National Defense Commission, Washington has "gone mad," the regime announced on state television. North Korea "has neither the need nor the willingness to sit at the negotiating table with the (United States) any longer," the statement said.

The commission, defined by the country's 1998 constitution as "the highest guiding organ of the military and the managing organ of military matters," is chaired by North Korean dictator Kim Jong Un. Its angry tone may be explained by Washington's rejection of Pyongyang's invitation to send the top U.S. nuclear envoy to the hermit kingdom for talks, Reuters said.

"It is our firm resolution to counteract through our own nuclear strikes (if the United States) provokes a nuclear war (against North Korea)," the statement said, "and (to) bring the (United States) to an early demise with our own pre-eminent cyberwarfare if the (United States) tries to bring us down through a cyberattack."

The reference to cyberattacks appears telling as President Barack Obama last year accused North Korea to be behind a massive hacking attack on Sony Pictures Entertainment, which was preparing to release "The Interview," a movie that portrayed Kim in a negative light.

In a Jan. 22 YouTube interview, Obama added that the Internet would eventually and inevitably penetrate even a country as reclusive as North Korea, according to Reuters.

"Over time you will see a regime like this collapse," the president said about the three-generation dynasty of Kim and his father and grandfather, Kim Jong Il and Kim Il Sung, who have ruled the country since its establishment in 1948.

South Korea, meanwhile, said it would continue its efforts to improve ties with the Communist North, irrespective the tensions between Pyongyang and Washington, the Korea Times noted.

Lim Byeong-cheol, a spokesman for the South's Unification Ministry, said his country's government strove to "build trust between South and North Korea through dialogue and cooperation."