US and British leaders George W Bush and Tony Blair on Tuesday endorsed a ‘vital role' for the United Nations in Iraq and called for world unity over the country when fighting ends.

Washington and London hope their agreed vision of the postwar stages in Iraq will placate anti-war nations such as France, Germany and Russia, and appease widespread international suspicion of US motives in Iraq.

"We are of course agreed, as we say in our joint statement, that there will be a vital role for the United Nations in the reconstruction of Iraq," Blair told a news conference after his summit meeting with Bush in Northern Ireland.

Bush used the same words, and added he wanted Iraq to move fast towards establishing an interim authority of Iraqis.

"We will move as quickly as possible to place governmental responsibilities under the control of an interim authority composed of Iraqis from both inside and outside the country," Bush told the news conference at Hillsborough Castle.

"The interim authority will serve until a permanent government can be chosen by the Iraqi people," he added.

"Rebuilding of Iraq will require the support and expertise of the international community. We are committed to working with international institutions, including the United Nations, which will have a vital role to play in this task."

But when pressed on what precisely the UN role would be, Bush mentioned only humanitarian work and 'suggesting' people for the interim authority.

Blair urged the world to avoid ‘endless diplomatic wrangles' over the future of Iraq like those over possible UN authorisation of force before the war started.

The British leader, who has stood by Bush throughout the crisis, said the ‘new Iraq' that would emerge after the war, would be run by the Iraqi people not by Britain, the United States or the UN.

Neither leader had news of Iraqi President Saddam Hussein's fate following US attempts to kill him earlier on Tuesday.

"I don't know whether he survived. The only thing I know is he is losing power," Bush said.

The two were briefed on their troops' overnight progress on Tuesday before talks on the second day of their summit. It was their third war council in a month.

While they took cheer from the US and UK forces' thrusts into Baghdad and Basra respectively, both men were said to be guarding against complacency.

"It is dangerous to take victory for granted in any way," was how Blair's spokesmen described their view.

As well as plotting Iraq's postwar future, their ambitious agenda for the two-day summit included the peace processes in the Middle East and Northern Ireland.