This agreement would not scrap the Anti-Ballistic Missile Treaty, which U.S. officials said remains the ultimate goal of negotiations with Russia, but would allow the administration to move ahead with the vigorous testing and development program it hopes to begin early next year.

"Testing will go on, but there will be no announcement of a U.S. withdrawal from the ABM Treaty," one official said. "That would be associated with a decision to deploy a system which will come later."

Under this interim arrangement, both countries would also set goals for slowly reducing the number of strategic warheads to between 1,750 and 2,250 each, officials said. This would be lower not only than the 3,000 to 3,500 warhead levels set under the START II treaty, but also the proposed ceiling for a START III pact that was reached by Presidents Bill Clinton and Boris Yeltsin in 1997. Implementation of START II, which was signed in 1993 by Bush's father and Yeltsin, was to have been completed by December 2007.

Each country now has more than 6,000 strategic warheads on land- and submarine-based missiles and long-range bombers, but Russia's arsenal is expected to decline sharply in the years to come because of obsolescence and lack of money.

The agreement would represent a substantial breakthrough nine months after Bush came into office and made missile defense his top foreign policy priority in the face of adamant Russian opposition to dropping the 1972 ABM pact. It would further underscore how far the two former Cold War adversaries have moved in transforming their relations, especially after the Sept. 11 terrorist attacks opened new areas of cooperation.

But preparations for the summit have also brought to a head the debate within the Bush team about how to achieve the goal of setting aside the ABM Treaty -- which prohibits a missile defense system of the type Bush envisions -- while trying to accommodate Putin's stated interest in reducing strategic nuclear weapons.

Bush and Putin will meet here Nov. 13 and then travel to Bush's ranch in Crawford, Tex., for two additional days of talks.

Though an interim deal within the context of the ABM Treaty now seems likely, some key officials in the Pentagon and their allies elsewhere in the administration have continued pressing for the United States to withdraw from the pact sooner rather than later. The final shape of the upcoming agreement has yet to be cast and different members of the administration are still debating whether to accept a deal that substantially loosens the treaty's testing restriction or to push for complete freedom to test, according to current and former officials familiar with the discussion.

"This has been subject to debate for quite some time and there's renewed interest given the fact that Bush has an opportunity to see Putin shortly," said an administration official. "It's an opportunity to move the agenda one way or another."

The internal administration efforts to influence the U.S.-Russia negotiations, one official said, were behind the announcement last week by Defense Secretary Donald H. Rumsfeld that the Pentagon would delay radar tests involved in the missile defense program. Rumsfeld opened a Pentagon news briefing by saying that the tests, scheduled for Oct. 24 and Nov. 14, were being put off because the radars to be used to monitor missile and rocket firings could be seen as violating the ABM Treaty.

Although this announcement was widely interpreted in the American and Russian media as meant to avoid a showdown with Moscow ahead of the summit meeting, U.S. officials said Rumsfeld did not have this in mind. Instead, officials said, he was trying to promote his goal of withdrawing from the treaty entirely as soon as possible by showing that the pact was already inhibiting the American testing program.

Defense officials pointed out that the two tests had already been delayed for technical reasons unrelated to the ABM Treaty. Moreover, Rumsfeld made his statement a month after the Ballistic Missile Defense Organization, the Pentagon office responsible for developing a missile shield, had been informed in an internal memo dated Sept. 24 that the radars involved in the tests could not be used in a fashion that violates the treaty.

Asked by reporters Monday whether his comments had been misleading, Rumsfeld said, "If one of those tests is canceled or has been canceled for technical reasons, so be it. All I know is, at the time I was asked what should they do, I said, 'Do not violate the treaty.' And if later there was a technical reason and we could not have used the radar anyway, that's life."

Senior administration officials said Rumsfeld and others who want to see the treaty quickly scrapped have been the most vigorous advocates of interpreting the ABM Treaty strictly. This allows them to make the case that the pact is already constraining the testing program and must go.

Others in the administration, including national security adviser Condoleezza Rice, have sought to depict greater room for compromise, saying for instance that Russia had said it does not see missile tests as a threat. Although Rice had argued in the summer the need for "maximum flexibility" from the treaty, she has stressed in recent days that Bush has the more modest short-term goal of ensuring that the pact does not constrain the testing and evaluation of missile defense technologies.

After meeting Russian Foreign Minister Igor Ivanov in Shanghai last month, Secretary of State Colin L. Powell said, "I have had some discussions with Russian colleagues of mine who suggest we can probably do more testing than we think under the treaty. . . . We are looking at that."

The group within the administration that includes Powell and Rice wants "to do everything we need to do on our timetable and accomplish all the other objectives with Russia all at the same time," a senior official said.

Noting that no missile defense architecture exists and therefore a deployment decision on any shield remains years off, another senior official said, "You could argue we shouldn't get rid of the treaty now and give the Russians an understanding." The official added: "We're working through all the issues now."

The prospect that the administration would reach an interim deal with Russia short of full withdrawal from the ABM Treaty has grown in recent weeks. At his meeting with Putin in Shanghai last month, Bush refrained from giving a deadline for a pullout from the treaty. After the meeting, both leaders sounded upbeat about the chances of reaching a deal.

An essential part of a new understanding with Russia would be an agreement over levels of offensive weapons. In a campaign speech on May 23, 2000, Bush said he wanted to reach "the lowest number of nuclear weapons consistent with our national security needs including our obligations to our allies."

The strategic warhead reductions now envisioned would be accomplished over a long period, in part because the Russians do not have the money to carry out the costly destruction of land- and sea-based intercontinental ballistic missiles, nor the facilities to store the weapons-grade uranium and plutonium from the warheads.

Under START II, reductions down to the 3,000 to 3,500 level are not supposed to be accomplished before the end of 2007. "We are already on the downslope dismantling the first of the 50, 10-warhead, Peacekeeper ICBMs and cutting the number of Trident ballistic missile submarines down from 18 to 14," said a U.S. official involved in the nuclear weapons program. "The question is how fast we go down," he said, "since the Russians will go much slower."

Staff writers Bradley Graham and Steven Mufson and researcher Lynn Davis contributed to this report.