North Korea has rejected US suggestions that it follow Libya's lead and give up its nuclear ambitions.
The US wants North Korea to shut down its nuclear facilities
Washington called on Pyongyang to renounce nuclear weapons to end its international isolation and qualify for economic aid.
But North Korea called the US proposal a "daydream".
The rebuff came despite the US saying it is to donate 50,000 tons of food aid to North Korea. It said the gesture was unrelated to the nuclear negotiations.
Senior US officials have urged North Korea to follow the example of Libya, which has seen most sanctions against it lifted after it gave up its weapons of mass destruction.
But Pyongyang dismissed the US proposal as "a sham offer not worthy of further discussion".
"The US is foolish enough to calculate that such mode
imposed upon Libya would be accepted by [North Korea] too," a spokesman was quoted as saying.
Pyongyang has said it will freeze its nuclear facilities, perhaps leading to their eventual dismantling, but only after the US provides energy aid, lifts economic sanctions and stops accusing it of sponsoring terrorism.
The BBC's Jonathan Head says although North Korea's tone sounds ominous, such statements are not unusual and do not mean it will abandon talks on its nuclear programme.
Washington is currently engaged in six-party talks with North Korea, China, Russia, Japan and South Korea to resolve the nuclear crisis in the Korean peninsula.
State department spokesman Richard Boucher said the donation of food aid, was "to help relieve the suffering of the North Korean people", not to influence the nuclear negotiations.
But he did say it would be "good" if the aid impressed the North Koreans and prompted them adopt a more favourable attitude in the talks.
Mr Boucher said the aid would be distributed through the World Food Programme.
He said the North was allowing more monitoring of food distribution and security.
Hundreds of thousands, perhaps millions, of North Koreans are thought to have died from famine in recent years.