David Mack, a former US
government official now with the Middle East Institute, told Al Jazeera he did not think "that this can be accomplished this year".
"Quite frankly, there is a war under way in Iraq. I don't think it's ever been possible to negotiate a status of forces agreement during a war.
"The American forces there are too large and there's too much fighting going on among different Iraqi sectarian groups to pull this off."
The presence of tens of thousands of foreign private security contractors in Iraq has been heavily criticised, especially after the killing last year of 17 Iraqis in Baghdad by Blackwater, a US company which protects American officials in the country.
December more likely
A majority of the Iraqi parliament wrote to the US congress last week rejecting a long-term security deal with Washington if it is not linked to a requirement that US forces leave.
|Satterfield: "We want to see Iraqi sovereignty |
strengthened, not weakened" [AFP]
"The majority of Iraqi representatives strongly reject any military-security, economic, commercial, agricultural, investment or political agreement with the United States that is not linked to clear mechanisms that obligate the occupying American military forces to fully withdraw from Iraq," the letter to the leaders of Congress said
Samir al-Sumaidie, Iraq's ambassador to the US, told Al Jazeera that he believed "there is a genuine desire on both sides to conclude an agreement that will regulate the relationship between the two countries and the two security forces".
He admitted that "we're talking about December in reality because the [UN] mandate of the American forces and all foreign forces will run out at the end of December".
"But there is a process to be finished and one stage of the process is to agree on the text [and] the target is to reach a text by the end of July and then start the process of ratification."
The ambassador said he did "expect some opposition" from some quarters in Iraq's parliament, but "the Iraqi government is serous about trying to achieve this deadline".
"We'll try to achieve it. We should try seriously to achieve it. If we don't achieve it then we'll consider the situation at that time but we have to make a serious and determine attempt to achieve it."
A senior Bush administration official close to the talks reportedly told the Associated Press news agency on Monday that it was "very possible" the US may have to extend the existing UN mandate which expires at the end of the year.
Iran has also opposed the agreement, suggesting that if permanent US military bases are established on Iraqi soil, the country could be used as a launching pad for attacks on neighbouring Tehran.
Iraqi media reports have suggested the US is seeking to keep as many as 50 military bases in Iraq indefinitely, control the nation's air space, and grant troops and foreign private contractors continuing immunity from prosecution under Iraqi law.
American diplomats and military officials have denied that Washington wants to create permanent bases in Iraq.
Source: Al Jazeera and agencies