The pact, agreed upon after nearly a year of gruelling negotiations with Washington, must still be approved by the Iraqi parliament, but Foreign Minister Hoshiyar Zebari said he expected that to happen by the end of the month.
It puts a closing date on a war that has been one of the defining political issues in the United States, the Middle East and around the globe for much of the past decade.
"The total withdrawal will be completed by Dec. 31, 2011. This is not governed by circumstances on the ground. This date is specific and final," cabinet spokesman Ali al-Dabbagh said of the pact, supported by 27 of 28 cabinet members.
Iraq cabinet approves security pact with U.S.