Speaking from Iraq on Friday, General George Casey told defence reporters at the Pentagon that by late next year the Iraqi military should largely be able to take the lead in their country's defence with support of transition teams from the United States and its allies.
He expects force levels to drop back to what has been the average of 138,000 by early February.
He said: "We just had the election, we're doing our assessments and I'll make some recommendations in the coming weeks here about whether I think it's prudent to go below that baseline."
Casey said that the two extra battalions that were sent to Iraq for election security would head home in January.
He said that US forces would still be in the lead in parts of Iraq until some time in 2007. Depending on the progress of the new Iraqi government ministries, he said, it would take until then for Iraqi security personnel to be able to take control of their forces across the country.
"We just had the election, we're doing our assessments, and I'll make some recommendations in the coming weeks here about whether I think it's prudent to go below that baseline"
General George Casey,
US commander in Iraq
Even with Iraqi forces in the lead, some US support would still be needed, he said. About 153,000 US troops are in Iraq now.
Casey also said the Iraqi police forces would not be able to take charge of internal security until late next year or early in 2007.
American public pressure
Casey's discussion of troop levels comes amid growing pressure from Congress and the American public to begin withdrawing US forces from Iraq.
The Pentagon has refused to give details of any withdrawal, but defence officials have said the Pentagon plans tentatively to halt the scheduled deployment of two brigades to Iraq.
Instead, smaller transition teams would be sent in to support and train Iraqi forces, and much of one brigade, currently in Kuwait, would return to its home base in Germany.
Coming in the aftermath of what US officials have described as a successful parliamentary election on Thursday in Iraq, Casey tempered his comments by saying that he expects fighters to step up their attacks to demonstrate that they remain a force to be dealt with.
A successful election may not
mark the end of fighting in Iraq
"We should not expect the insurgency to just go away because of yesterday's great success," he said.
"But we should expect it to be gradually weakened and reduced as more and more Iraqis adopt the political process, and the root causes of the insurgency are addressed by the new Iraqi government and by the coalition."
Casey said conditions along Iraq's border with Syria had improved, leading to a decrease in bombings. He said allied forces' operations had restored Iraqi control of the border, and the Syrians appeared to have acted against foreign fighters coming through there. As a result, he said, suicide attacks had declined from more than 60 in June to fewer than one a day this month.
In contrast, he said Iran appeared to have tried to meddle the most in the Iraqi election.
"And I believe that they will continue to attempt to influence the formation of this government over the coming weeks to get a government that they believe is supportive of their interests," Casey said. "That is worrisome, and it is a challenge for us."
House votes against pull-out
Battles among various factions, particularly in Sunni-dominated regions of the country, helped to hold down election-day violence, he said, as Sunni Muslims fought back against al-Qaida efforts to prevent them from going to the polls.
Meanwhile, for the second time in as many months, the House of Representatives rejected calls to withdraw US troops from Iraq. Democrats said the vote was politically driven and designed by majority Republicans to limit debate on the war.
Iraqi troops are expected to
control their affairs by next year
By 279 to 109, the House approved a resolution saying the chamber is committed "to achieving victory in Iraq" and that setting an "artificial timetable" would be "fundamentally inconsistent with achieving victory".
Democrats voted against the resolution by 108 to 59, while 34 of them voted "present", a rarely used option that signals neither support nor opposition. That split underlined divisions within the party over alternatives to the Iraq war policies of George Bush.