The two-day delay came against a backdrop of relentless violence that has seen at least 40 US soldiers die in the past 10 days, putting the overall death toll for US soldiers at 1818 since the March 2003 invasion of Iraq.
US President George Bush vowed to "stay the course" in Iraq despite the killings and a new aAl-Qaida threat on Thursday warning the United States and Britain of more death and destruction.
Iraqi President Jalal Talabani said the meeting to end the deadlock on drafting a new constitution and resolving outstanding questions was postponed for Kurdish leader Massud Barzani.
"The meeting of leaders was delayed from today to Sunday in order to allow Barzani to attend a meeting Saturday of the Kurdish parliament before coming to Baghdad as the head of a delegation of Kurdish parliamentary groups," said a statement from Talabani's office.
The issues yet to be decided on include federalism, official languages, the relation between religion and state, the name of the republic, the rights of women and the question of the oil-rich centre of Kirkuk which Kurds want included in their own autonomous region.
Iraqi leaders have pledged to draft the new basic law by 15 August ahead of a referendum in mid-October, to be followed by national elections in December and possible formation of a new government by early 2006.
"We are worried about comments from some on the committee regarding federalism, Kurdish rights, democracy and women's rights"
Adnan Mufti, head of the Kurdish regional parliament
Mahmud Othman, a Kurdish member of the constitutional committee, said the delay was to give the Kurdish autonomous parliament time to discuss the charter.
"The leadership in Kurdistan asked for the Kurdish committee members to come back and explain to our parliament what has been discussed in Baghdad," said Falah Mustafa, a spokesman for Barzani's Kurdistan Democratic Party (KDP).
"We are worried about comments from some on the committee regarding federalism, Kurdish rights, democracy and women's rights," Adnan Mufti, head of the Kurdish regional parliament and senior official of Talabani's Patriotic Union of Kurdistan Party said.
Endorsing the charter
He said the Kurds were ready to endorse the charter "if all parties understand a constitution should be based on rights for all Iraqis, if not we cannot reach an agreement."
"We are insisting on federalism, there is no way to have a unified Iraq without federalism."
Mufti said he hoped Baghdad would accept Kurdish federalist demands, but added three issues could be problematic - the future of Kirkuk, the name of Iraq and the role of Islam.
"We want Islam to be a main source of legislation, but not the main source," Mufti said. "Iraq is a country for all - Christians and Yezidis, as well as Sunni and Shia."
Iraqi premier Ibrahim al-Jaafari said meanwhile the Shia cleric Ayat Allah Ali Sistani was ready to accept a federal Iraq.
"Sistani does not disagree with the principle of federalism if the Iraqi people choose it," Jaafari said after meeting the Iranian Iraq-based reclusive cleric at his home in the southern Shia city of Najaf.
Iraqi police have been suffering
This could boost hopes of an agreement between members of a committee tasked with drafting the constitution by the 15 August deadline.
The conference is due to report back by 12 August and any matters still unresolved will be put to the full parliament for decision by majority vote.
Iraq will be a parliamentary republic with a strong prime minister and a figurehead president, according to the latest draft of the constitution.
As Iraq waited for the upcoming meeting, confrontations have been persisting between US and Iraqi forces and fighters who regard any arrangements made after the US invasion of Iraq in 2003 as illegal.
Also in Najaf, al-Jaafari discussed the constitution with anti-US Shia cleric Muqtada al-Sadr, whose supporters have led two bloody uprisings against US troops.
Al-Sadr appeared to give his blessing to efforts to draft the constitution but said his movement would not be directly involved, due to the continued presence of foreign troops in Iraq.
"I have no representative in the writing of the constitution and I distance myself from such political affairs because of the occupier, but he who wants to take part can," he said.
Iraqi leaders were due to meet in Baghdad on Friday to hammer out various differences that remain among them over the wording of the constitution, with just 10 days left before a draft is due to be presented to parliament.
Death in custody
An Iraqi being held in US custody has died of his wounds after being captured in battle, the US military said on Friday.
The man, identified as "a 45-year-old Iraqi male," died on Thursday "from multiple organ failure as a result of gunshot injuries sustained while engaging coalition forces," said a statement.
The man was captured and taken to a combat hospital on 24 July before being transferred to a field hospital at Abu Ghraib, west of Baghdad, "where he developed a serious tissue infection" which "eventually resulted in multi-organ failure and death," it said.
"So in common with every other nation that is here, we are looking to draw down our forces and eventually withdraw completely from this country"
Major-General James Dutton
On 28 July the US military announced that a male prisoner had died at Camp Bucca, a US military detention camp in far southern Iraq due to complications from malaria.
Another Iraqi detainee being held at the camp died on 19 April.
British and other troops will be withdrawn from Iraq's relatively quiet southern provinces when Iraqi security forces are capable of assuming control, a British general said on Friday.
"So in common with every other nation that is here, we are looking to draw down our forces and eventually withdraw completely from this country," said Major-General James Dutton.
"When we do that is entirely condition based. And we will do it when we judge that the Iraqi security forces are capable enough of taking charge," he said.
Dutton commands the 13,000 troops that now control four southeastern provinces in Iraq, which includes the cities of Basra and Nasariyah.
US-led forces say they will leave
when Iraqi troops are ready
The force includes nearly 8000 British and 3000 Italian soldiers, as well smaller contingents from other countries.
Dutton said any decision on the timing of their withdrawal would be taken jointly with the Iraqis.
"Ultimately we are planning for a complete withdrawal of coalition forces from Iraq. I think it will inevitably be in stages," he said.
"Certain areas of the country will be able to take charge of their own security sooner than others," he said.
Because the southern provinces have been relatively quiet, US-led forces will likely be drawn down in that region before US forces begin their drawdown from the central, western and northern regions that have been the centre of a fierce insurgency, he said.
Currently, about 5500 Iraqi army soldiers are in the southeastern sector and their number is projected to grow to about 9000 by next June.