Planning for a short-term bulge in troop levels comes as US commanders, according to defence officials, are also working towards cutting the current force by 20,000 to 30,000 soldiers by the middle of next year, contingent on progress in Iraq's political process and in developing Iraqi security forces.
The increase in troops also coincides with a spike in the number of Americans killed fighting the uprising after a US-led invasion toppled president Saddam Hussein in 2003.
Since 30 July, at least 41 US soldiers have been killed in Iraq, including 18 on 3 August alone.
A Pentagon tally released on Monday listed 1829 US military deaths since the start of the war in March 2003. Another 13,700 soldiers have been wounded in action.
Chief Pentagon spokesman Lawrence Di Rita said the Defence Department might delay the scheduled departure of an unspecified number of the 139,000 US troops currently in Iraq, achieving a short-term increase in the size of the force as more troops flow into the country as previously planned.
Donald Rumsfeld expects a rise in
violence close to the Iraq polls
Di Rita did not say how big an increase was envisioned. The Pentagon temporarily raised US troop levels by about 20,000 to roughly 160,000 ahead of the historic 30 January elections.
Asked if the size of the US force would reach 160,000 again, Di Rita said: "It could be more, it could be less."
Defence Secretary Donald Rumsfeld and other Pentagon leaders have predicted a rise in violence by fighters attempting to disrupt the upcoming voting.
The Iraqis have a 15 August deadline for drafting a new constitution, which would face a referendum on 15 October. Elections for a new government are scheduled for two months later.
"We'll have a lot of flexibility to be able to let the forces stack on top of one another during the rotation [of troops in and out of Iraq] so that we can have a greater capability during key points," Di Rita said.
"We altered the rotations of units during the January election. And I think it's perfectly plausible to assume we'll do the same thing for this election," said Di Rita, adding that final decisions had not been made.
US troops in Afghanistan will be
increased near September polls
The military previously had announced it was augmenting the US force in Afghanistan ahead of 18 September parliamentary elections by sending an airborne battalion of 700 to 800 82nd Airborne Division paratroopers from Fort Bragg, North Carolina, to join the 17,600 American troops already in the country.
Di Rita did not rule out the possibility of dispatching a similar unit from the US to Iraq but said it was more likely an increase in troop levels would come about as a result of delaying the scheduled departure of soldiers already serving there while new ones arrived as planned.
US Army soldiers generally serve tours of no more than a year on the ground in Iraq at a time, with Marines serving seven-month stints.