US President George W Bush has warned that insurgents in Iraq will step up their attacks ahead of next month's referendum on a new constitution.
A female suicide bomber targeted would-be soldiers in Talafar
But he said both US and Iraqi forces were ready to meet the threat.
Mr Bush is facing difficult times, with record low approval ratings and opinion polls showing a majority of Americans no longer support the war in Iraq.
His comments came on the day eight people were killed in the first attack in Iraq by a female suicide bomber.
She pushed her way into a crowd at an army recruitment centre in Talafar, northern Iraq, said witnesses and army officers.
The Islamist group al-Qaeda in Iraq later purportedly claimed in an internet message that a "blessed sister" mounted the attack on its behalf.
President Bush warned that the run-up to the 15 October referendum would be a focus for further attacks.
"We can expect they'll do everything in their power to try to stop the march of freedom," said President Bush in the White House Rose Garden.
He was speaking after talks with two top US generals in Iraq, and added: "Our troops are ready for it."
And he pointed to the killing of Abu Azzam, al-Qaeda's supposed number two in Iraq, as an example of the US strategy of "hunting down high value targets".
Mr Bush was flanked by his generals during his Rose Garden speech
But US military casualties in Iraq are fast approaching the psychologically significant figure of 2,000, says the BBC's Oliver Conway in Washington.
And, in his latest comments, Mr Bush is seeking to prepare the American people for even more deaths, our correspondent adds.
The president said he had asked Gen George Casey, top US commander in Iraq, and Gen John Abizaid, US Central Command chief, to brief Congress on the war in Iraq.
"The support of Congress for our troops and our mission is important and Americans need to know about the gains we have made in recent weeks and months," he said.
"They need to know the way we're adapting our tactics, and the way we're changing our strategies to meet the needs on the ground."