Bush administration officials say they do not expect an early response by North Korea to the U.S. proposal presented in Beijing Wednesday aimed at solving the crisis over that country's nuclear program. But they say the plan addresses Pyongyang's needs for increased aid and recognition while at the same time providing for a verifiable end to its nuclear weapons capability.

Officials here say the North Korean delegation at the six party talks in Beijing doesn't have the political authority to respond to the U.S. plan, and that it may take the leadership in Pyongyang several weeks or longer to come up with a definitive reply.

But they are defending the proposal offered Wednesday in Beijing, saying it provides a clear pathway to a nuclear weapons-free Korean peninsula that would open the door to a new relationship with North Korea.

The plan, developed in close coordination with South Korea and Japan, is considered the first detailed U.S. overture to North Korea since President Bush took office three years ago.

The text takes up several pages, but in essence it calls for North Korea to declare its intention to dismantle its nuclear weapons program, and for a three-month preparatory period during which its nuclear weapons and key weapons-producing equipment would be disabled.

In return, during the three-month span, North Korea would get immediate aid in the form of fuel oil shipments, from China, Russia, Japan and South Korea while the United States would offer a "provisional" guarantee for North Korea's security.

The preparatory period would be followed by the internationally-supervised dismantlement and elimination of all the country's nuclear-related facilities and the removal of weapons and components.

The payoff for Pyongyang for this would be multi-lateral security assurances, long-term aid commitments and steps to ease its political and economic isolation including the prospect of the lifting of long-standing sanctions against North Korea by the United States.

At a news briefing, State Department spokesman Richard Boucher said the new U.S. plan deals with the major flaws of the now-abandoned 1994 "agreed framework," under which Pyongyang was to have frozen its nuclear program in return for two western-designed nuclear power plants.

"This is not a freeze, this is not the agreed framework. The agreed framework was a protracted freeze until a reactor was completed," he said. "This is achieving the goal of de-nuclearization on a practical time-frame, and in a way that does reverse the problems that have occurred over the past several years, first starting by constraining them and then moving on to dismantling them. But it goes further than that and it reaches a stable de-nuclearized basis for more positive relations between North Korea and the rest of the world."

The Bush administration had previously said that it would not stand in the way of other parties providing aid to North Korea if it froze its nuclear program.

But it had said the United States itself would not provide any benefits short of an agreement for the complete, verifiable and irreversible dismantling of the program (CVID).

Officials here say the new formulation assures that North Korea would move quickly from a freeze to CVID, while also addressing the security and other concerns North Korea has raised at the six-party talks, which began last year.

They say it is based on the model under which Libya moved to rejoin the world community when it agreed last December, after months of negotiations with the United States and Britain, to the supervised dismantling of its weapons of mass destruction programs.