Speaking at a ceremony at the Al-Shaab stadium complex in central Baghdad, Maliki said December 31 was "a feast for all Iraqis" and marked "the day Iraq became sovereign". "I announce today, the 31st of December, which witnessed the completion of the withdrawal of US forces, to be a national day," Maliki said. "We call it Iraq Day."
"Today, you are raising the Iraqi flag across the nation, and unifying under that flag. Today, Iraq becomes free and you are the masters."
US troops completed their withdrawal Iraq on December 18, nearly nine years after Washington launched a controversial war to oust Saddam Hussein. At their peak, American forces in Iraq numbered nearly 170,000 and had as many as 505 bases.
In 2008, Baghdad and Washington signed a deal which called for all US soldiers to leave Iraq by the end of 2011. Efforts to keep a significant American military training mission beyond year-end fell through when the two sides failed to agree on a deal to guarantee US troops immunity from prosecution.
In addition to a Marine detachment responsible for securing the US diplomatic mission, 157 US soldiers remain in Iraq, under the authority of the embassy and charged with training domestic forces on US-purchased equipment.
Maliki's remarks came amid a festering political standoff in Iraq, with authorities having charged Sunni Vice President Tareq al-Hashemi with running a death squad and Maliki calling for Sunni Deputy Prime Minister Saleh al-Mutlak to be fired.
Mutlak and Hashemi's Sunni-backed Iraqiya party has boycotted parliament and cabinet meetings. Hashemi, who is holed up in the autonomous Kurdish region, rejects the accusations.