US Nukes Present Obstacle at 6-Party Talks

[S]ince the start of the Bush Administration the US has, together with Iraq, classified North Korea as a country of "chronic military concern" in its nuclear posture review (NPR). As if to back that up the Bush Administration has pursued the development of small nuclear warheads that could be used to target underground North Korean facilities, while at the same time it has developed something called "Conplan 8022," which outlines the use of nuclear arms against the North in time of conflict. There is considerable merit to the North's claims that there is an American nuclear threat.
That leads to reason to believe the North will demand something is done about the nuclear threat against it, including a negative security assurance. It will bring up instances where it has been fooled by the US in the past and demand legally binding assurances. The Bush Administration, however, has strengthened America's nuclear hegemony and said it could use nuclear arms against a biochemical attack, so it will not be accommodating to such demands.
Demands by the US that the North take the first step by giving up its nuclear program and the North's demand that the US take action on the nuclear threat as one of the corresponding actions it needs to take in response will probably make finding agreement difficult.