U.S. Defense Secretary Leon Panetta on Sunday signed a document officially ending the Iraq War as the last U.S. troops pulled out of the country. Before Panetta signed the official document, code named EXORD 1003 Victor, Mod 9, the last batch of US combat forces left Iraq on Sunday morning and crossed into the neighboring country Kuwait. The US troop withdrawal started earlier before the Dec. 31 deadline set by U.S. 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. About 4,500 U.S. soldiers and hundreds of thousands of Iraqis have died since the war started in 2003.