"As long as the US has not awakened from the foolish dream of 'system collapse', the DPRK's songun (army-first) policy and its nuclear deterrent will continue to prove its validity and vitality", a North Korean foreign ministry spokesman said on Wedensday.
The spokesman, quoted by Pyongyang's official news agency, was using the North's official name, the Democratic People's Republic of Korea.
"The US is dreaming of 'system collapse' in the DPRK, a solid and unique Korean-style socialist system rare to be found in the world," the spokesman said.
In reality it was the US-style capitalist system which was on the verge of collapse due to the economic crisis, the spokesman said.
He cited major demonstrations against corporate greed which began in Wall Street and spread internationally.
The spokesman also said that "wild words" from the US left North Korea sceptical about the US's willingness to hold dialogue with it.
South Korea's Yonhap news agency has said the two countries will hold a second meeting next week in Geneva to discuss ways to restart stalled six-nation talks on the North's nuclear disarmament.
There has been no official confirmation as yet.
The two sides held a first round of discussions in New York in late July to assess the chances of resuming the talks.