A law urging more human rights in North Korea passed unanimously by the US Congress showed nuclear talks were meaningless because America was "hell-bent" on toppling the communist state, the North's foreign ministry said.
The North Korean Human Rights Act of 2004, which cleared its final legislative hurdle in Washington on Monday, "rendered the dialogue and negotiations for solving the nuclear issue meaningless", said the North Korean Foreign Ministry.
"This has deprived the DPRK of any justification to deal with the US, to say nothing of the reason for holding the six-party talks for settling the nuclear issue," the ministry said in an overnight statement published by the official KCNA news agency.
North Korea, whose official title is the Democratic People's Republic of Korea (DPRK), has kept the world guessing about whether it intends to attend another round of talks on its nuclear ambitions with the United States, China, Japan, Russia and South Korea.
The parties to talks aimed at ending a two-year impasse over its nuclear programmes failed to hold a planned fourth round of negotiations in September.
The North is being urged to scrap all its nuclear programmes in exchange for security guarantees and energy aid.
With Democratic challenger John Kerry differing with President George W. Bush on calls for direct talks with North Korea, analysts say Pyongyang is awaiting the result of next month's US presidential election.
US Ambassador to South Korea Christopher Hill said North Korea should not wait for the election.
"I think they need to understand that whoever is elected president, there is absolutely no tolerance for dealing with a country that maintains nuclear weapons programmes," Hill said in a speech in Seoul on Tuesday.
"I would hope that they would not waste more time and would figure out a way to negotiate it," he said. The foreign ministry repeated a frequent North Korean threat to accelerate its arms build-up, saying the human rights law gave Pyongyang "no option but to put spurs to increasing the deterrent force to counter the US by force to the last".
"It is nothing strange that the US is hell bent on its hostile Korea policy," KCNA said.
Last week, North Korean Vice Foreign Minister Choe Su-hon reiterated that his country had weaponised the fuel from 8,000 reprocessed spent fuel rods that experts say could raise Pyongyang's nuclear cache from one or two bombs to eight.
The North Korean human rights legislation unanimously passed the US House of Representatives in July and cleared the Senate unopposed with slight revisions two months later. Monday's House approval of the revisions prepares the act for Bush's signature.
The legislation calls for the expansion of human rights for North Korea's 22 million citizens and allots funds to support refugees who have fled hunger and repression in the North.
The North Korean Foreign Ministry denounced the law as "full of anti-DPRK poisonous clauses".
Last month, British Foreign Office minister Bill Rammell returned from a trip to North Korea saying government officials had said Pyongyang put a lower priority on human rights than the West.
Rammell said he urged Pyongyang to allow a visit by the UN special rapporteur for North Korea to investigate persistent reports of vast forced labour camps, torture and other abuses.