"I assured them that the United States believes strongly that the Iraqi constitution should provide equal rights before the law for all Iraqis regardless of gender, race, ethnicity, religion or sect ... There can be no compromise."

He went on: "Tomorrow the Iraqi leaders begin to meet to finalise the draft constitution.

"I am hopeful that as these leaders gather and as the final document emerges they will lay a foundation for a new Iraqi nation where all of its citizens are able to participate and no community is oppressed, marginalised or excluded."

Shi'ite leaders, whose majority was oppressed under Saddam Hussein and thrust to power in a January election made possible by the U.S. invasion, say they do not want to emulate Shi'ite neighbour Iran in imposing Islamic clerical rule, which critics say discriminates against women and followers of other faiths.

Some Iraqis complain Islamists are already trying to curb personal behaviour such as women's employment and alcohol sales.

WASHINGTON EYES TEHRAN

Washington, at daggers drawn with Tehran since the Islamic revolution of 1979, is also wary of Iranian influence.

But it had previously limited public comment on the drafting of the constitution, anxious not to be seen to be controlling a process it hopes can draw the sting from the revolt, legitimise and strengthen the Iraqi government and let it begin pulling out U.S. troops after a new election at the end of the year.

Kurdish and Sunni leaders spelled out key demands ahead of Sunday evening's talks at the home of President Jalal Talabani.

A prominent Sunni member of the drafting panel, which is due to present its work to parliament by Aug. 15, accused Islamist Prime Minister Ibrahim Jaafari of tending toward religious rule by meeting Grand Ayatollah Ali al-Sistani on Friday and telling voters that Sistani broadly favoured some of his plans.

"It gives the impression people must follow these opinions, which means clerical rule," Saleh al-Mutlak of the National Dialogue Council told Reuters after Jaafari met Sistani in the Shi'ite holy city of Najaf after Friday prayers. "The Shi'ite religious authority is interfering in political affairs."

Jaafari said Sistani, who rarely appears in public, had voiced cautious support for some kind of federal structure for the new state -- a issue that concerns some Sunnis who fear the encroachment of already autonomous Kurds on northern cities and their surrounding oilfields and Shi'ite control of southern oil.

KURDS STAND FIRM

In the Kurdish parliament, regional president Masoud Barzani assured legislators he would defend their interests in seeking a share of oil, a continued role for their non-Arab peshmerga militia forces and limitations on the scope of Islamic law.

"We should be flexible in negotiations but that does not mean we should haggle over our demands," said Barzani, who led forces that, with U.S. help, drove out Saddam's troops in 1991.

Another Kurdish leader, Ghafour Makhmouri, told lawmakers: "All our demands for the panel are red lines that cannot be crossed. We will not soften them. They are our minimum rights."

Late on Friday, southwestern Baghdad was rocked by explosions and gunfire for several hours. A Reuters journalist in the area saw groups of insurgents moving through, attacking Iraqi and U.S. forces with machineguns and rockets.

It was the latest of several coordinated infantry assaults on Iraqi government forces which analysts say demonstrates a fair level of military expertise among guerrilla commanders.

The U.S. military said in a statement on Saturday that tanks, helicopters and ground troops had fought back, killing six insurgents and capturing 12. An Iraqi soldier was killed and another wounded in one of two suicide vehicle attacks, it said.

In all, the U.S. military said there were four attacks, including with mortars and a suicide car bomb that was stopped by a U.S. tank shell: "The Iraqi army took the fight to them and succeeded. This success is what will help secure and stabilise Iraq," Major Liston Edge said in a statement, voicing U.S. hopes that Iraqis can take over protecting the new government.

American and Iraqi forces also pressed on with an offensive west of the capital, around the city of Haditha. U.S. forces said 24 suspects were in custody. A local doctor, Waleed al- Hadithi, said six civilians were killed and eight wounded. (Additional reporting by Waleed Ibrahim, Haider Salaheddin and Andrew Hammond in Baghdad, Shamal Aqrawi in Arbil and Majed Hameed in Haditha)