WASHINGTON – The top American commander in Iraq says he wants to continue the troop buildup there until next spring, amid debate over whether to bring some forces home months earlier than that.

When he delivers a much-anticipated report to Congress on Monday, Army General David Petraeus said he expects to advise that there could be a gradual reduction of forces beginning in the spring because of some of the successes achieved so far with the escalation ordered by President Bush in January.

“Based on the progress our forces are achieving, I expect to be able to recommend that some of our forces will be redeployed without replacement,” General Petraeus said in an e-mail to the Boston Globe.

“The bottom line is that … I do not envision that the U.S. would need to send more troops,” he said, adding that commanders are planning for how remaining troops will be deployed around Iraq “as the surge of forces inevitably runs its course.”

Administration officials said General Petraeus and U.S. Ambassador Ryan Crocker recommended to Mr. Bush that he stand by his current war strategy.

But they also said that Mr. Bush was considering announcing by year’s end that there could be a symbolic reduction in troops.

Senator Warner, Republican of Virginia, a former Armed Services Committee chairman, Navy secretary, and key player on military issues on Capitol Hill, has suggested that some troops be brought home by Christmas as a gesture.

America would be hard-pressed to maintain the buildup level in Iraq indefinitely. Officials say the number of troops there now has climbed to a record 168,000 and is moving toward a peak of 172,000 in the coming weeks – a level that could extend into December – but that it is only because of troop rotations. That is, as some brigades leave and others come in there is a temporary overlap.

The escalation ordered in January essentially added some 30,000 troops to the pre-buildup figure of around 130,000.

Mr. Bush himself suggested that modest troop cuts may be possible if military successes continue, but he gave no timeline or specific numbers. Speaking to reporters Wednesday during his attendance at the APEC summit in Australia, he restated his view that decisions about troop levels should be based on recommendations from military commanders.

Reducing troops before spring runs the risk, General Petraeus and other commanders have said.

The five brigades sent as part of the buildup arrived from January to June, and the first will complete its 15-month tour in April.

General Petraeus is one of many who are advising Bush on Iraq. The Joint Chiefs of Staff met with Mr. Bush last week and conveyed its concern that the troop buildup is increasing strain on the forces, with the Army in particular hoping for an end to the surge because of the long and repeated combat tours it has caused.

Mr. Bush met privately at the Pentagon with the service chiefs and Defense Secretary Gates in preparation for decisions about how long to sustain the buildup, whether to change course this fall, and how to restore vibrance to the heavily stressed Army and Marine Corps.

The Petraeus appearance before Congress will follow the release of a host of grim assessments of conditions in Iraq over the past several weeks – providing fresh impetus for Democrats demanding troop withdrawals.

An independent panel led by retired Marine General James Jones recommended that the Iraqis assume more control of their nation’s security and that American forces, seen as an occupying and permanent force, should step back. Its report, presented to Congress yesterday, contended that “significant reductions, consolidations and realignments would appear to be possible and prudent.”

The Jones panel also found that Iraq’s security forces would be unable to take control in the next 12 months to 18 months and recommended that its national police force be scrapped and entirely rebuilt because of corruption and sectarianism.

The Government Accountability Office, the investigative arm of Congress, reported Tuesday that Iraq has failed to meet 11 of its 18 political and security goals. The agency’s head, U.S. Comptroller David Walker, was scheduled to appear today before the Senate Armed Services Committee to discuss the report.