Camp Victory, built around the late Saddam Hussein's opulent al-Faw Palace in western Baghdad, was the largest of the 505 American military installations in Iraq and headquarters for all U.S. military operations in the country during the 8 1/2-year war.
There was no public ceremony marking the transfer of the facility.
A commemoration event was held Thursday to recognize the sacrifices of U.S. and Iraqi soldiers in the war, ABC News reported.
"[Because] of you and the work those of you in uniform have done, we are now able to end this war," Biden said.
As of Thursday, 4,486 Americans had died in the war in Iraq.
Although the United States has until Dec. 31 to withdraw all of its forces from Iraq, U.S. military commanders have said that the bulk of American troops would be out by mid-December.
ABC said more than 20,000 troops have left Iraq in the past four weeks and 13,000 remain in the country.
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