Bush Administration officials confirmed Wednesday that the United States plans to store rather than destroy some of the nuclear missiles being dismantled as part of an arms reduction agreement with Russia.

Back in November, President Bush promised his Russian counterpart, Vladimir Putin, that the United States would cut its nuclear weapons arsenal by two-thirds over the next ten years. That would mean a reduction in nuclear warheads from about 6,000 down to somewhere in the area of 1,700 to 2,200.

But a nuclear strategy review released by the Defense Department Wednesday says not all of those nuclear warheads being dismantled will be destroyed.

Assistant Secretary of Defense J. D. Crouch told reporters at the Pentagon that the administration has not yet decided how many of the roughly 4,000 nuclear warheads and bombs slated for decommissioning will be destroyed and how many will be put into storage and available for redeployment at a later date.

"What we will end up with is a situation where some weapons will move off and stay in the responsive capability of the United States," he said. "Others will be earmarked for destruction and will be put in the queue for destruction and others will remain in the inactive stockpile. So this is going to shift over time. It is also going to shift as a result of factors that we cannot foresee at this time."

The nuclear strategy plan is mandated by Congress and this latest version also calls for increased spending to prepare for the possibility of future underground nuclear bomb tests.

Presidential spokesman Ari Fleischer told reporters at the White House that the administration is keeping its options open when it comes to future nuclear testing. "The president has said that we will continue to adhere to the no-testing policy. We would never rule out the possible need to test to make certain that the stockpile, particularly as it is reduced, is reliable and safe. So he has not ruled out testing in the future, but there are no plans to do so," he said.

U.S. defense officials say keeping the dismantled nuclear weapons in storage will enable them to be ready for potential threats in the future. But some arms control advocates are critical of the administration's approach, saying the strategy could encourage the Russians to stockpile rather than destroy some of their nuclear weapons as well.