WASHINGTON - US Defense Secretary Leon Panetta on Sunday signed a document officially ending the Iraq War, after the last US combat forces left that country.

According to Pentagon Press Secretary George Little, Panetta signed the document, code named EXORD 1003 Victor, Mod 9, a little before 7 am, Eastern Standard Time. The document puts an official end to the war that lasted nearly 9 years.

US Air Force airman wait to board the last Air Force flight out of Ali Air Base near Nasiriyah, en route to Kuwait Dec 17, 2011. [Photo/Agencies]

Before Panetta signed the official document, the last batch of US combat forces in Iraq departed on Sunday morning and crossed into neighboring Kuwait.

The war left about 4,500 US soldiers and more than 100,000 Iraqis dead, in addition to the countless wounded and 1.75 million Iraqis displaced.

The US military's final departure came earlier before the Dec 31 deadline set by US President Barack Obama to fulfill his election promise to pull all the American troops out of Iraq as agreed in a security pact between the two countries in 2008.

In his weekly address on Saturday, Obama marked the end of the Iraq War, saying "Iraq's future will be in the hands of its own people."