The United States is working on proposals for a new United Nations Security Council resolution to address the changed situation in Iraq, American diplomatic sources say.
The Security Council was deeply divided over the Iraq war
Among the ideas reported to be under consideration are a complete lifting of economic sanctions against the country, and a phasing out of the UN's role in controlling its oil revenues.
The BBC's UN correspondent, Greg Barrow, says the Bush administration is clearly seizing the initiative in proposing plans for a new era in Iraq following the downfall of Saddam Hussein's regime.
He adds that their proposals envisage control of the country's vast oil reserves being placed at the disposal of a transitional authority that would oversee reconstruction - probably under the guidance of the US.
UN officials have greeted the ideas cautiously, amid concern over the legality of any attempt to take over control of Iraq's oil.
UN Under-Secretary General Shashi Tharoor said such a move would need international support if it was not to be contested.
"As long there isn't a legitimate recognised government of Iraq there are some real questions such as: How does anybody sell the oil because who has legal title to Iraq's oil?" he said.
"All of these things need to be resolved, and I think an American initiative would be very welcome, provided it is eventually agreed by the other members."
Our correspondent says the new proposals clearly go much further than many Security Council members would like.
The French have so far only proposed a suspension of sanctions pending the return of UN weapons inspectors - with a full lifting of the sanctions regime only coming once the inspectors have decided that Iraq is free of weapons of mass destruction.
There is also concern in some quarters that the Security Council should not be seen to be legitimising the US-led military intervention in Iraq and anointing any new American-backed transitional authority.
In other developments:
- Coalition forces have killed "several" Iraqi paramilitaries and destroyed their vehicles after coming under attack near the north-western city of Mosul, the US military says
- The first post-war international meeting of Iraqi political groups begins in the Spanish capital, Madrid
- Thousands of Shia Muslims in the Iraqi holy city of Karbala demonstrate against the American presence in the country following Friday prayers
- US Defence Secretary Donald Rumsfeld says a "vocal minority" of pro-Iranian Shias will not be allowed to seize power in Iraq
- The UN refugee agency says it is planning to help up to half a million Iraqi refugees return home from exile.
American officials are questioning Iraq's former Deputy Prime Minister, Tariq Aziz, following his arrest.
They are keen to discover if Mr Aziz - a high-profile figure in the ousted government - has information on the whereabouts of Saddam Hussein and any weapons of mass destruction.
Born in 1936, near Mosul, northern Iraq
Studied English literature and became a journalist
The most senior Christian in the toppled regime
Enlisted US support for war on Iran
Met US President Ronald Reagan at the White House in 1984
Was Saddam Hussein's deputy for more than a decade
Mr Aziz, 67, is reported to have surrendered to US-led coalition forces in the Iraqi capital Baghdad after several days of negotiations.
He served as Iraqi foreign minister for many years, and was internationally the most recognisable face of the Iraqi Government after President Saddam Hussein.
A former Iraqi exile who has declared himself governor of Baghdad, Mohammed Mohsen Al-Zubaidi, told the BBC that he gave the Americans the information that led them to arrest Mr Aziz and his family.
American forces have also detained a former Iraqi intelligence chief, Farouk Hijazi, near Iraq's border with Syria.
Mr Hijazi also served as Iraqi ambassador to Turkey and Tunisia, but - unlike Mr Aziz - he is not among the 55 leading Iraqi officials the Americans have been seeking.
Mr Aziz is the 12th person on that list to have been caught, according to the US. As a member of Iraq's Revolutionary Command Council, he was wanted for war crimes against Kuwait, Iran and his own people.
There had been fears that regime leaders would flee Iraq, perhaps into Syria.
But arrests continue to be made in Iraq, and officials such as UK Foreign Secretary Jack Straw say they believe Saddam Hussein is still inside his country.