Iraqi negotiators have proposed a timetable for U.S. withdrawals that would see combat troops leave the country by October 2010, although Washington has not yet agreed to it, a senior Iraqi official said.

If agreed, the timetable would mean the administration of President George W. Bush effectively adopting a schedule very close to that proposed by Democratic presidential candidate Barack Obama, who opposed the 2003 US invasion of Iraq.

"As of last night that was one of the issues being discussed between the two sides. There is no agreement yet, but this is what the Iraqis are asking for," said the official who is close to the negotiations.

The schedule proposed by Iraqi negotiators would see US forces withdraw from the streets of Iraqi cities by the middle of next year and combat troops return home by October 2010. Some American support units could stay on for another few years.

Washington and Baghdad are negotiating a deal to allow US forces to stay in Iraq beyond the end of this year, when a UN mandate expires. There are now 144,000 US troops in Iraq.

Bush has long resisted imposing a firm timetable for withdrawals, but has begun speaking of setting "time horizons" as Iraqis have begun making clear that they would like to see a date for the Americans to go home.

White House spokesman Dana Perino, in Beijing accompanying Mr Bush, said no announcement on an agreement was imminent and it was too early to discuss the dates of a pullout.

"It's premature to say what the aspirational goals and time horizons are going to be. But we are continuing to work with them on our negotiations, on those issues," she said.

She cited Mr Bush's earlier statement that any such goals would be "conditions-based".

Iraq's ambassador to the United Nations, Hamid Bayati, said on Thursday an agreement on the US forces' status was close and that the government expected to put it to parliamentarians when they return from summer recess in September.