The United States on Tuesday welcomed the approval of Iraq's constitution in a referendum, describing it "a landmark day" for efforts to build democracy in the war-torn country.

"It's a landmark day in the history of Iraq. We congratulate the Iraqi people," White House spokesman Scott McClellan said hours after the final results of the referendum were officially made public.

Iraq's new constitution, the first post-Saddam charter, was ratified by 78 percent of the voters. Twenty-one percent said No.

"The political process is continuing to move forward in Iraq, and it's an encouraging sign to see more and more people participating in the process," said McClellan.

The weekend national referendum's results were accurate and followed international standards, the spokesman quoted UN observers as saying.

Source: Xinhua