The United States has signalled to North Korea that it may be willing to offer the secretive Stalinist state security guarantees if it agrees to abandon its nuclear programme.
The US has refused to offer a non-aggression treaty
US Secretary of State Colin Powell said North Korea was continuing to demand a credible assurance that the US was not planning to attack or invade, and that Washington was exploring ways to resolve that issue.
He said Washington wanted North Korea to not only say it did not support nuclear weapons on the Korean peninsula, but also to show it was ready to remove its capability in a way that could be independently verified.
Mr Powell's comments come just days after it emerged that during recent six-party talks in Beijing, North Korea had threatened to test a nuclear weapon.
Mr Powell said he was still hopeful that there will be further talks on de-nuclearising the Korean Peninsula and that he will be pursuing the issue in the coming weeks.
Correspondents say there is likely to be a second round of talks between the two sides and other regional powers soon.
"The only thing that North Korea has said to us that they would
like to see from the United States is a security assurance that we are not planning to attack them or invade them," Mr Powell said.
"We have said that and they wish to see this assurance provided in some form that they would have confidence in."
The smiles at the six-way talks masked massive tensions
"That is what we are focusing on - them making it clear to
the world that they not only say they do not wish to see
nuclear weapons on the peninsula, but they are
actually prepared to act on that by removing their capability,
and we are looking at ways in which we can give them the kind
of assurance that they say they need," Mr Powell added.
In the past the US has refused to offer North Korea any kind of formal treaty promising non-aggression in return for North Korea agreeing the stop its nuclear programme.
And US officials deny that there has been any change in policy towards North Korea here.
The North Korean nuclear crisis erupted last October when
US officials said Pyongyang admitted to a secret programme
to enrich uranium for nuclear weapons, violating its agreements
with the US and its international commitments.