Lieutenant General Lance Smith, deputy commander of the US Central Command, said on Friday that additional troops may also be deployed if necessary to secure the country before the vote.
"We are talking mainly about extending some units," Smith said. "We will make further assessment as we get a little bit closer and understand what the impact of Falluja has been in the entire country.
"The issue is not just numbers. The issue is really about experienced troops during this period of time of expected increased violence," the US commander said.
His comments came after a top marine commander, Lieutenant General John Sattler, claimed the assault on Falluja has "broken the back of the insurgency".
The campaign in Falluja fuelled
attacks elsewhere in Iraq
But Smith said US commanders will know they have succeeded when they are able to bring under control "a widespread campaign of intimidation".
"We have certainly had a significant impact on the insurgency, but we know that the important part is going to be to follow on with this success and not allow a safe haven to exist any place, like Ramadi or Baquba or some of those other cities where we know these folks go," he said.
Smith also dropped hints that elections may not be held in Falluja.
"And so it could be that even without, say, a city like Falluja voting, that there will be adequate representation by the Sunnis to feel or look like it was legitimate representation for all the parties involved."