Iraq's prime minister has appealed for other countries to write off its debts, at the start of a summit called to try to rebuild and stabilise the country.
Nouri Maliki urged delegates at the talks in Egypt to help "build a united, democratic and federal Iraq".
Rich nations and regional powers are meeting for two days of talks in the Red Sea resort of Sharm el-Sheikh.
American officials say US Secretary of State Condoleezza Rice will meet her Syrian counterpart at the conference.
The last high-ranking diplomatic contact between Washington and Damascus was in January 2005.
Ms Rice has hinted she could also meet the Iranian foreign minister on the sidelines of the summit.
Mr Maliki said Iraq needed to free up funds to invest in much-needed reconstruction projects.
"We call on all the friends and brothers participating in this conference to forgive Iraq all its debts in order to enable it to start the projects," he said.
However, Saudi Foreign Minister Saud al-Faisal said only that his country "has expressed its readiness to alleviate some of the debts on Iraq".
Earlier, US and Iraqi officials had said Saudi Arabia was committed to cancelling 80% of Iraq's $17bn (£8.5bn) debt to it, the Associated Press reported.
Meanwhile Russia was demanding the right to buy up oil fields in return for writing off debt, Iraq's finance minister, Bayan Jabor, told Reuters.
Thursday's conference was called to endorse a five-year International Compact for Iraq (ICI), under which Iraq will institute reforms promoting national reconciliation, and will receive major financial assistance.
United Nations Secretary General Ban Ki-moon said: "Iraq is at a critical juncture.
"As the Iraqi people strive to achieve these goals they should be able to count on the active support of Iraq's neighbours and the international community."
Separate talks on Friday, involving all Iraq's neighbouring countries and other major powers, will focus on Iraq's security.
Condoleezza Rice says she would speak to Manouchehr Mottaki
Iran and Syria are due to attend, as well as representatives of the US, G8 and EU .
The conference got under way against a background of continuing violence in Iraq.
The US said a rocket strike on Baghdad's heavily fortified Green Zone had killed four US government contractors, all from the Philippines.
Meanwhile Iraq said that a leading Sunni militant, Abu Omar al-Baghdadi, who headed the group called the Islamic State in Iraq, had been killed.
The presence of ministers from the US, Iran and Syria at the talks in Egypt has sparked speculation of possible talks between them on the sidelines.
Ms Rice said she would not avoid an exchange with Iranian Foreign Minister Manouchehr Mottaki should it happen.
"I think I can handle any question that is asked of me," she said.
"If we encounter each other and wander to other subjects I am prepared to address them at least in terms of American policy."
Iranian President Mahmoud Ahmadinejad said he would welcome "honest dialogue" with the US in Egypt.
SUMMIT DELEGATIONS INCLUDE
But he warned that it would be a "mistake" for the US to think negotiations would result in Iran scaling back its nuclear programme when sanctions and diplomatic pressure have not yielded results.
Such a meeting would mark the first bilateral talks between ministers from the two countries since the United States cut relations in 1980.
There has been little contact between them ever since the Iranian revolution and the seizure of the US embassy in Tehran in 1979.
But the open question is whether even holding direct talks will lead to America and Iran coming to any sort of agreement, says the BBC's Jonathan Beale, who is travelling with Ms Rice.
The Bush administration still accuses Iran of meddling inside neighbouring Iraq - a charge Iran has strongly denied - and Washington refuses to discuss Iran's nuclear programme until Tehran suspends its uranium enrichment.
The US also charges Syria with allowing foreign fighters to enter Iraq through the long border between the two neighbours - something Damascus denies.