The Bush administration presented a more specific proposal for resolving the North Korean nuclear crisis Wednesday, offering the North the possibility of energy aid from South Korea, security assurances and other benefits during a three-month test period if it promises to disclose and end its nuclear weapons programs.

U.S. negotiators at talks among six nations -- the United States, North Korea, China, South Korea, Japan and Russia -- on the standoff also backed away from hard-line language calling for the "complete, verifiable and irreversible" dismantling of the programs. The administration had insisted that the North Korean government agree to the language in two previous rounds of the talks but said it was now willing to consider other wording to describe the same goal.

One senior U.S. official described the proposal as a "repackaging and elaboration of things we have said before" and said it was likely to be rejected by the North Koreans. But other U.S. officials described it as a legitimate effort to flesh out a U.S. plan for ending the stalemate.

In any case, the proposal represents an attempt by the Bush administration to address criticism from its allies as well as domestic critics. The allies complain that the administration has not been flexible enough in the talks, while critics such as Democratic presidential candidate John F. Kerry have described its strategy as a failure that has allowed North Korea to produce nuclear materials undisturbed for nearly 20 months.

North Korea's delegation did not immediately respond and indicated it wanted to confer with superiors in the capital, Pyongyang. A diplomat at the talks said the Chinese were not pleased with aspects of the plan, and Russian officials said it would be impossible for North Korea to accept it.

U.S. officials in Beijing and Washington acknowledged they drafted the new proposal largely because of pressure from South Korea and Japan. Both nations, as well as China, the host of the talks, have been pushing the Bush administration to show more flexibility and let North Korea demonstrate it is willing to dismantle its nuclear program. An official in Washington said "alliance management" was one of the key motivations for making the proposal.

But a White House official said the proposal also was designed to gauge North Korean intentions. "It is a test," he said, speaking on condition of anonymity. "It is a pragmatic and reasonable way forward."

A senior U.S. official who briefed reporters in Beijing on condition of not being identified said the plan is "more tangible and more specific" about what North Korea stands to gain by abandoning its nuclear programs and "spells out in detail" what North Korea needs to say in its promise to disarm.

Previously, U.S. officials had privately outlined a three-stage approach for ending the crisis, placing much of the onus on North Korea and providing only vague suggestions about what it would receive in return. The proposal outlined Wednesday includes stages tied directly to North Korea's performance in dismantling its nuclear programs, and various elements could be suspended or slowed if North Korea lagged in one or more areas, officials said.

Under the plan, South Korea and possibly other countries could begin providing heavy fuel oil to the North's battered economy immediately if the North Korean leader, Kim Jong Il, promises to dismantle the country's plutonium and uranium arms programs, U.S. officials said. The idea was floated by South Korea at the last round of talks and was neither rejected nor endorsed by the United States.

U.S. officials said this fuel would aid North Korea with its desperate energy situation and provide an incentive to begin preparations for dismantling its programs. Once North Korea began to display and secure its materials and weapons -- and its claims have been verified by U.S. intelligence -- the United States and the other nations at the negotiations would issue provisional security assurances. This formula would effectively say the countries had "no intention to invade or attack" North Korea. The United States also would lay the groundwork for a study of North Korea's non-nuclear energy needs, discussions on lifting economic sanctions and removing North Korea from a U.S. list of state sponsors of terrorism.

After Defense Secretary Donald H. Rumsfeld protested, President Bush rejected a State Department proposal to immediately offer security assurances to North Korea at the same time that fuel shipments were started by South Korea, said an administration official familiar with the interagency discussions.

North Korea would be given only three months to halt and disclose all of its nuclear activities, including a secret uranium enrichment program that it says does not exist, and to begin securing and destroying nuclear materials under the supervision of international monitors, the officials said. Otherwise, these preliminary benefits would be halted.

North Korea has said it needs nuclear weapons because of Bush's "hostile policy" and has demanded written security guarantees from the United States before dismantling its programs.

The proposal does not specify a timetable of benefits that the North would receive in exchange for specific steps, as North Korean negotiators have previously demanded.

The Bush administration is retreating from its demand for the "complete, verifiable and irreversible dismantlement" of the North's programs because the phrase "seems to inflame sensibilities," one official said. Another administration official said the United States was using slightly softer language -- asking North Korea to dismantle its programs "in a permanent, thorough and transparent manner subject to effective verification" -- because North Korean negotiators declared in a working-level session last month that the previous wording was "culturally offensive."

Kessler reported from Washington.