The Taoiseach will meet Saudi Arabia's King Abdullah today as part of his five-day Gulf States trade mission.
Bertie Ahern's meeting with the Saudi monarch comes hours after King Abdullah's talks with US Secretary of State Condoleezza Rice.
Dr Rice is promoting President Bush's new policy on Iraq and urging greater international involvement in the region.
In a speech last night on the Middle East at the King Faisal Foundation in Riyadh, Mr Ahern warned that important lessons must be learned from international policy in Iraq.
He said: "It is clear that there have been catastrophic failures in policy towards Iraq. But while there are extremely important lessons to be learned from these past failures, the focus has to be above all on the present and future."
He warned that progress was only possible if shared political institutions were developed, existing territorial borders were respected and inter-communal reconciliation was promoted.
"None of us can afford the further brutalisation, division and isolation of the historic nation of Iraq," he added.
Mr Ahern also said the volatile situation across the Middle East continued to represent the greatest single threat to world peace and a comprehensive settlement was more urgently needed than at any time over the past 60 years.
He added that it was the most significant foreign policy challenge facing the European Union. It was also at the top of Ireland's foreign policy agenda and was regularly pursued by the Irish Government at EU and UN level.
This week's cross-border trade mission, organised by Enterprise Ireland, brings 170 employers from 114 firms to Riyadh, Abu Dhabi and Dubai.
Enterprise Ireland believes Irish companies have the potential to take increased Middle East market share in the key sectors of telecommunications, IT, construction, banking, public sector/utilities and education and e-learning services.