Officials noted that Bush had repeatedly voiced his opposition to the Comprehensive Test Ban Treaty during the 2000 presidential campaign, calling it "fatally flawed."

The Senate, previously controlled by Republicans, declined to ratify the treaty in 1999, to the dismay of U.S. allies.

Now that the Senate is led by Democrats, some analysts say the treaty could be revived. Despite that possibility, Bush will not try to withdraw the CTBT because, as one official said, there was "little precedent" for taking a treaty back once it had been sent to the Senate.

Before leaving office, former President Bill Clinton had urged the new Senate to take up the treaty again.

But the Bush administration disagrees.

"There is little confidence that the treaty can actually be verified," a senior administration official said. "With a treaty flawed in that way, it doesn't further nonproliferation efforts."

Some analysts had expected Democrats to launch an effort to revive the test ban treaty after they took 50-49 control of the Senate last month.

The Bush administration has no desire to see a new debate on the treaty.

"There is no support within the administration for the treaty to be taken up for consideration again," the official said.

Delaware Democratic Sen. Joseph Biden, who replaced North Carolina Republican Sen. Jesse Helms -- an opponent of the treaty -- as head of the Senate Foreign Relations Committee, supports the CTBT, but it needs a two-thirds majority to be ratified.

In January, just before Bush took office, Gen. John Shalikashvili, the former chairman of the Joint Chiefs of Staff, presented a report to Clinton urging the United States to ratify the treaty.

More than 150 countries have signed the CTBT, but it can come into force only when 44 potentially nuclear-capable countries ratify it.

Shalikashvili, who spent 10 months conducting a review of the contents of the treaty by interviewing nuclear experts, weapons designers and senators, concluded that ratifying the CTBT would increase national security, and the security benefits of the treaty would outweigh disadvantages.

He had said the Senate's vote not to ratify the treaty raised concern at home and abroad that the United States might be walking away from its traditional leadership of international nonproliferation efforts.