United States President George W Bush [Images] has reaffirmed that the war in Iraq is winnable and that he would not have deployed US troops unless victory was assured.

Buoyed by the reported success of a troop-surge strategy in Baghdad, he said, "The fight would be tough but the war against "extremists and murderers" would succeed," The Australian daily reported on Thursday.

In a joint APEC conference with Australian Prime Minister John Howard in Sydney, he expressed confidence about military advancement in Iraq after a visit two days ago to Anbar province.

"The province I saw wasn't lost to the extremists. The place I went had changed dramatically -- fundamentally because the local people took a look at what al Qaeda stands for," he said adding, "We're not interested in death and destruction."

Bush said he would not have committed US troops if he had not been convinced the objective was achievable.

Earlier, he defined success in Iraq as having a country that would be able to govern, sustain and defend itself and be responsive to the needs of its people.

"He says the security situation is changing so that reconciliation can take place. I met with sheiks that are tired of violence. They are reconciling after decades of tyranny," he said.

Meanwhile, Howard reaffirmed Australian troops would remain in Iraq as long as the coalition government he led remained in power.

But he appeared to leave open the possibility of a change in role for the 900 diggers serving in Iraq, including combat operations from which they have so far been removed.