US President George W Bush is holding a video conference with his senior generals in Iraq to discuss the escalating violence there.
Mr Bush has said they may focus on changing tactics to combat the unrest, but not the overall military strategy.
In his radio address, he said that he would employ "every necessary change" to quell the surge in attacks.
There was more violence on Saturday as four people died and 15 were injured in a suicide bomb attack on a Baghdad bus.
The bomber was aboard the bus and one Iraqi soldier at the scene told Reuters news agency that a surviving passenger said she had overheard the bomber speaking to someone on the phone just prior to the blowing himself up.
According to the AFP news agency the bus, which was set alight by the blast, was packed with women and children who had been shopping in preparation for the Eid holiday, which marks the end of the Muslim holy month of Ramadan.
Children's clothes and toys, as well as celebration fireworks, littered the ground and the wreckage of the bus, which exploded close to the Sarafiyah bridge in central Baghdad.
In his weekly radio broadcast, Mr Bush acknowledged that Ramadan had been a "rough" period for people in Iraq, with a rise.
But he added that the US "will not pull our troops off the battlefield before the mission is complete".
His comments come amid fears that Mr Bush's Iraq policy could cost his party control of Congress in forthcoming polls.
Opinion polls suggest two-thirds of Americans think the president's strategy in Iraq has failed.
The BBC's Justin Webb in Washington says the figure could translate into catastrophic election losses in mid-term elections next month, which might see the Democrats back in power in Congress and the Bush presidency becoming the lamest of lame ducks.
Leaders of the opposition Democratic Party have sought to put further pressure on Mr Bush by calling for the start of a phased withdrawal of US troops from Iraq by the end of the year.
They also want the president to convene an international conference to support what they call a political settlement in Iraq.
Amid the mounting domestic pressure for a change of strategy in Iraq, Mr Bush was consulting on tactics with Gen John Abizaid, the top US commander in the Middle East, and Gen George Casey, the leader of the US-led coalition in Iraq.
"Our goal hasn't changed, but the tactics are constantly adjusting to an enemy which is brutal and violent," he said.
White House spokesman Tony Snow said the meeting was one of a series of regular consultations and had been scheduled "for weeks".
Concerns about rising violence in Iraq have been further fuelled by clashes between Iraqi police and gunmen loyal to the radical cleric, Moqtada al-Sadr, in the southern town of Amara.
Medical sources say 31 people were killed in street battles on Thursday and Friday, and many more were injured.
The Iraqi army has now been deployed to quell the violence and Kareem Abdullah Shayal, one of the soldiers deployed said things were now calm in the city.
In another development, the Iraqi president's security adviser said Iraqi forces trying to improve security in Baghdad were under-funded, badly trained and poorly equipped.
Wafiq al-Samarra'i said that sometimes the insurgents and death squads had better weapons than the security forces trying to combat them.
The comments come a day after the US military said there had been a "disheartening" 22% rise in attacks in Baghdad this month, despite a two-month-old security operation.
Launched in June, Operation Together Forward is a joint US and Iraqi security drive in which thousands of extra troops have been deployed in Baghdad.
On Wednesday, Mr Bush said the escalation of violence in Iraq "could be" comparable to the 1968 Tet Offensive against US troops, which helped turn public opinion against the Vietnam War.
With 73 US soldiers killed so far, October is on course to become the deadliest month for US forces in Iraq for two years.