US President George W Bush has ruled out signing a non-aggression pact with North Korea, but repeated that the United States has no intention of invading the communist state.
North Korea says it has reprocessed 8,000 spent nuclear fuel rods
Washington is pushing for further six-party talks with Pyongyang, to try to persuade it to give up its nuclear ambitions, after negotiations ended in August in Beijing without success.
But North Korea said it was not interested in further such talks - which involved Japan, South Korea, China and Russia - unless the US was prepared to discuss a non-aggression treaty.
Mr Bush was speaking in Bangkok on Sunday ahead of a summit of Pacific Rim nations.
He said he planned to talk to Asian leaders about how to
defuse nuclear tensions in the region.
"We think there's an opportunity to move the process
forward and we're going to discuss it with our partners," Mr Bush told reporters.
The president said perhaps there were other ways to convince Pyongyang that the US would not attack, but he did not elaborate.
Earlier this week, North Korea threatened to "physically display" its nuclear deterrent.
Some analysts interpreted the statement as a hint that it would test a nuclear bomb - a move that would dramatically intensify the year-long crisis.
But the US and South Korea dismissed Pyongyang's statement as mere sabre-rattling.
The crisis began last October when US officials said North Korea had admitted to having a secret nuclear programme, in defiance of a 1994 agreement.
The US and its allies stopped the fuel aid supplies to North Korea, which had been part of the 1994 pact.
North Korea retaliated by kicking out United Nations weapons inspectors, reactivating its mothballed Yongbyon power plant, and pulling out of a key anti-nuclear treaty.
It is very difficult to verify North Korea's claims about its nuclear programme, but some analysts believe the Yongbyon plant is capable of generating enough plutonium for about one weapon a year.
North Korea also says it has reprocessed 8,000 spent nuclear rods - which the US believes is enough to produce a handful more bombs.