US Secretary of State Colin Powell has said the UN will definitely have a role to play in post-war Iraq - but the precise nature of the role is yet to be decided.
Powell: Coalition commanders will act in partnership with other bodies
Mr Powell was speaking at Nato headquarters in Brussels, after a day of talks with European foreign ministers.
He said the US-led coalition would work in partnership with other organisations but would reserve for itself the "leading role in determining the way forward".
He added that Nato member states had been receptive to the idea of Nato peacekeeping in Iraq, but stressed that no definite proposals had yet been tabled.
Nato Secretary General George Robertson and Greek Foreign Minister George Papandreou, whose country holds the EU's rotating presidency, both spoke earlier of an emerging transatlantic consensus on the future of Iraq.
UN role in Iraq
Nato role in Iraq
Timing of handover to Iraqis
Who pays for reconstruction
The aim of Mr Powell's visit - his first since the start of the US-led invasion of Iraq - was to rebuild relations damaged by bitter disagreements in the run-up to the war.
European ministers said they would be pressing Mr Powell to agree to a central role for the UN.
Mr Powell said Washington hoped UN Secretary General Kofi Annan would appoint a co-ordinator to supervise "the flow of humanitarian aid coming from UN organisations".
But he stressed that the potential role of the UN had yet to be decided, and that resolutions had yet to be drafted.
The US administration is reported to be divided on the issue.
Mr Powell said the work of reconstruction and rebuilding of Iraq would require the international community to work together.
BBC Brussels correspondent Chris Morris says if the UN is not put in control of Iraq, the EU will have to consider what financial contribution it is prepared to make.
Correspondents say France, Germany and Russia are still bitterly opposed to anything that would legitimise the war.
But there have been signs of a more conciliatory approach from all three governments.
The German Chancellor, Gerhard Schroeder, told parliament in Berlin on Thursday that his country hoped the war would end quickly with the fall of what he called the current Iraqi dictatorship.
However, he stressed that Germany remained opposed to the war, and said Iraqi resources must remain under the control of its people.
On Wednesday, Russian President Vladimir Putin said his country did not want the United States to fail in its war in Iraq.
The talks in Brussels between Mr Powell and the French Foreign Minister, Dominique de Villepin, were described as "friendly, frank and turning towards the future".
The current US plan for the future of Iraq is reported to envisage a key role for an American administrator - retired general Jay Garner - who would run Iraq in conjunction with US and British forces, until an "interim Iraqi authority" can be set up.
Mr Powell said the US wanted to "quickly bring in individuals who can establish an interim Iraqi authority so that people can quickly see that their own representatives are moving into positions of authority".
The interim authority would then hand over to a fully fledged Iraqi Government.
One of the undecided questions is how long the process would take.
One State Department official has said the occupation could last two years.
But the UK and Germany have been stressing the need for Iraqi people to take control of their country as quickly as possible.
In a separate development, the Swedish Foreign Minister, Anna Lindh, said Mr Powell had told her the US would not attack Syria after it had won the war in Iraq.