"We want a permanent solution that is irrevocable," the chief US diplomat said during a press conference here with the Republican speaker of the House of Representatives, Dennis Hastert.

Powell underlined, however, that the US government is not seeking an accord like the one agreed with Pyongyang in 1994, which he said had contributed to current rifts.

"Some would suggest that we should just go back to the way it was done 10 years ago. But the way it was done 10 years ago left that (nuclear) capability in place and also allowed the North Koreans to think they might be able to sell this again, allow them to go and find another way of developing nuclear weapons through enriched uranium technology," Powell said.

Under the 1994 accord, North Korea's government was given oil deliveries and aid in exchange for mothballing the Yongbyon plant, which had the capability of producing weapons-grade nuclear material.

Powell reaffirmed the US government will continue to address the matter within a multilateral framework, Washington wants North Korea's neighbours to participate in negotiations on the issue.

Earlier Tuesday, the White House denied press reports that it would offer North Korea a non-aggression guarantee if the northeast Asian nation stops its nuclear weapons programs.

WAR.WIRE