"Iraqis must find it within themselves to reach out to one another and address issues on which they may differ," said UN Secretary-General Kofi Annan to a meeting attended by representatives of some 80 nations.
"Without an inclusive process, security initiatives are unlikely to yield enduring results," he added, echoing political analysts who say including more Sunni Arabs in decision-making could help defuse unrest.
The Shia-led panel charged with drafting a constitution for Iraq by 15 August agreed last week to raise Sunni numbers in the body, but US and EU officials will press Iraqi officials at the conference for further reassurances on the Sunni role.
"The international community is saying to the Iraqis that they should be as inclusive as possible, particularly of the Sunni community," US Secretary of State Condoleezza Rice said on the eve of the conference.
The conference - a result of US President George Bush's trip to Europe in February to mend fences two years after the Iraq war sparked rifts - will also urge Baghdad to stay on track to hold fresh elections by the end of the year, officials said.
Iraqi Foreign Minister Hoshyar Zibari said in the Wall Street Journal that efforts must concentrate on political and economic reconstruction and establishment of the rule of law through reform of the legal infrastructure.
"The purpose of this conference is primarily political, to send a clear message that the international community will stand by the people of Iraq," he wrote.
Zibari (L): Focus must be on
The meeting will steer clear of lingering transatlantic sensitivities over the US-led war, such as the continued refusal of France and Germany and other anti-war countries to offer troops, and is not intended as a donor conference.
Instead it will offer a show of world support for Iraq and give interim Iraqi Prime Minister Ibrahim al-Jaafari a platform to pitch for specific help in reconstruction and reform.
"Iraq has massive needs as far as basic services are concerned, including health, security and other economic infrastructure," al-Jaafari said. "We hope this conference will focus energies and increase the potential for aid."
Yet Iraqi unrest clearly remains a major obstacle to the foreign investment needed to rebuild Iraq and to help overcome a post-war unemployment rate put at over 50%.
"That is difficult while you have violence because private investment, private companies have security problems," said Danish Foreign Minister Per Stig Moller, noting Western efforts to train Iraqi forces to take over more security tasks.
The final communique at the conference will call on Iraq's major creditors to give generous debt relief, said an EU diplomat, who declined to be named.
It will also pledge support to Baghdad's efforts to join bodies such as the World Trade Organisation, the diplomat said.
Leading creditors Saudi Arabia and Kuwait will be among 80 countries represented at the meeting, yet conference organisers are looking more for statements of willingness to consider relief rather than any specific accords.
Rice (L) says Iraqis need to be as
inclusive as possible
Iraq accumulated $120 billion of debt during Saddam Hussein's era, mostly to fund a 1980-1988 war with Iran, although tens of billons of dollars were forgiven last year.
Finance Minister Ali Allawi said on Tuesday the government would convene a donors' meeting in Amman next month to accelerate disbursement of billions of dollars of aid pledged in 2003 by European and other countries.
Little of the $15 billion in non-US aid pledges made at that time has been spent because of violence, disagreements among donors and graft in Iraq, Iraqi officials say.