Prime Minister Tony Abbott has blasted in his strongest terms yet the US management of Iraq following the 2003 invasion, branding it a period of "chaos and confusion".

During a visit to Baghdad on Sunday, Mr Abbott hinted he could bolster Australian troop numbers in the war-torn country. It came as Fairfax Media learnt that Australian special forces soldiers in Iraq have begun operating "outside the wire" by accompanying local troops beyond Baghdad.

Mr Abbott met with his Iraqi counterpart and discussed what further help Australia could give the government beyond the current commitment, which includes 200 special forces advisers and RAAF airstrikes, for the fight against the brutal Islamic State group.

He used conspicuously strong language to slam the post-2003 handling of Iraq led by the US administration of George Bush and Dick Cheney, and strongly supported by former Prime Minister John Howard, who is Mr Abbott's political mentor.