WASHINGTON -- Secretary of State Colin Powell says he hopes to break a stalemate over North Korea's nuclear weapons programs by joining together with that country's neighbors in negotiating a security agreement with the communist-ruled nation.

Speaking Friday with a small group of reporters, Powell said North Korean nervousness about a possible U.S. attack is a major obstacle to an agreement to dismantle Pyongyang's nuclear weapons programs.

"They think we are still an enemy and we're after them, and we won't be satisfied until the regime is gone," he said.

In the search for a model multinational agreement that could be relevant to current conditions, Powell said his aides have been looking for historical precedents involving security assurances.

"My folks have come up with models that span 80 years," Powell said, declining to cite examples. "We will explore ideas with our friends in the weeks ahead."

Six-party talks held in Beijing in late August were inconclusive and there has been no agreement to hold follow-up discussions.

Mixed signals

In addition to the United States and North Korea, the process involves China, Japan, Russia and South Korea, all of which, along with the United States, agree that North Korea should dismantle its nuclear weapons programs.

But Pyongyang has spent much of the past year moving ahead with development of these programs. It also has been sending mixed signals about its willingness to continue the six-party discussions.

North Korea sees its budding weapons program as the best way to prevent an attack. Powell hopes the United States and North Korea's neighbors can eliminate that concern through a formal, written multilateral agreement.

For almost a year, the North has been demanding a bilateral nonaggression pact with the United States. Washington believes any such negotiation would not take into account the stakes that North Korea's neighbors have in the issue.

Powell will have a chance to exchange ideas with other participants in the six-party format when he travels to Thailand next week for an Asia-Pacific Economic Cooperation foreign ministers conference.

Top diplomats from most Asian and Pacific Rim countries will be attending. Powell leaves for Thailand on Thursday.