"In certain areas Iraq certainly can take care of its own security, this has been proven in the provinces of Anbar and Babil.
"And clearly Iraqis can cope at a provincial level for most of the time, however they do need Americans not on the streets but ready to come back to help them out if things really do go badly," he said.
Robert Gates, the US defence secretary, said that "pretty dramatic" consequences would follow if the status of forces agreement (Sofa) which would govern the US military's role in Iraq, falls through.
Gates said in Washington this week that the door was "pretty far closed" on further negotiations towards a security deal, although he emphasised that efforts were continuing.
"The consequences of not having a Sofa and of not having a renewed UN authorisation are pretty dramatic in terms of consequences for our actions," Gates said.
Gates said there was "great reluctance" to include further changes, but "if they [Baghdad or the US congress] were to come up with something we haven't thought of, or identify problems we missed some way, we would have to take that seriously".
"So I don't think you slam the door shut. But I would say it's pretty far closed."
A status of forces agreement would replace the current UN mandate - which expires on December 31 - as the legal basis for the US military presence in Iraq.
Iraq's cabinet unanimously called for changes to the draft now under review, despite US warnings that time was running out to finalise a deal.
Hoshyar Zebari, Iraq's foreign minister, said on Wednesday that Washington had agreed to consider Iraqi suggestions on amendments to the draft pact but that it was unlikely to accept a drastic revision.
"Yes, they are going to listen to the changes... We will give the amendments in writing. They will study it and get back to us. That is the usual pattern," he said.
"In my opinion and based on my follow-up for the negotiations, I do not think there will be structural amendments. Maybe it will touch the wording and descriptions, possibly, but the backbone of the pact is what has already been agreed on."
|There have been protests against the US-Iraq security deal [AFP]
Geoffe Morrell, a Pentagon spokesman, said on Wednesday that he had not "heard specifics on the possibility of reopening negotiations".
But he accused Iran, Iraq's eastern neighbour, of trying to "meddle" in US-Iraq affairs.
"In its most destructive, devious and deadly ways, it has to do with the flow of arms and weapons into Iraq," Morrell said.
"But there are, of course, counterbalancing negatives, one of which is clearly an attempt by the Iranians to undermine, undercut, derail the Sofa agreement," he said.
Iraq's Al-Sharqiya television reported that ministers from both the largest Sunni bloc - the National Concord Front - and the ruling mainly Shia grouping, the United Iraqi Alliance, wanted amendments.
But Gates and other US officials stressed that the current document should be acceptable to both sides.
According to Gates, there are "only two alternatives: the Sofa or a renewed UN mandate, and going back to the UN at this point there is no assurance that you get a clean rollover".
David Isenburg, a security analyst with the Cato Institute, told Al Jazeera that an extension to the UN mandate would only postpone examination of the differences between Baghdad and Washington.
"All they can get the UN is, at most, a one-year extension of the current mandate. That would leave all the current issues between Iraq and the US unresolved," he said.
The Bush administration earlier played down the Iraqi cabinet's decision to seek further negotiations.
"We knew it was going to take a little while to get this done," Dana Perino, the White House spokeswoman, said on Tuesday.
"We knew that the Iraqis would have several steps to go through."
'Forces not ready'
But Michael Mullen, chairman of the US joint chiefs of staff, said that time was running out for Baghdad to back the deal, which was originally due to have been completed by the end of July.
He cautioned that when the current UN mandate runs out on December 31, Iraqi security forces "will not be ready to provide for their security".
Mullen said Iraq risked security losses of "significant consequence" unless it approved an agreement that provides a legal basis for US forces to remain in the country.
Isenburg told Al Jazeera that both sides were "playing hardball in the negotiations, as [one] would expect".
The draft agreement could pose a problem to Barack Obama, the Democratic candidate for the US presidency, should he win the race for the White House, he said.
"One important thing to note about this agreement is that it is currently constituted to keep US troops through to the end of 2011. Senator [Barack] Obama said that if he gets into office he will have all US troops out in 16 months. So the agreement would lock him into keeping troops beyond where he wants to be," Isenburg said.