London, Aug. 9 : A deal that would establish a timeline for U. S. combat troops to withdraw from Iraq is not as close as recent reports would indicate, a senior U. S. official said on Friday.

"We don''t have a deal yet," the official from the U. S. Embassy in Baghdad said.

"Every time it looks like it''s in shape, it takes another twist and turn," the official said on the condition of anonymity because the discussions are ongoing.

The Independent quoted him as further saying that: "We''ve been making a lot of progress lately, and we''re hopeful we''ll come to a complete agreement soon. We certainly aren''t there yet."

The official said both sides are eager to strike a deal, but the talks are in "constant flux."

Both sides are rushing to seal a deal before a key U. N. mandate governing foreign troop presence in Iraq expires December 31.

Failing to reach a deal, the U. S. will have to try to get a temporary extension of the U. N. mandate, which could face resistance from Russia and China on the U. N. Security Council.

Analysts, lawmakers and government officials say failing to strike a deal by year''s end could mean heavy risks for U. S. troops, leaving them without combat authority or protections from prosecution in January 2009. (ANI)