The US vice president has pressed Iraq's leaders to settle their differences and form a government, almost six months after the country's election failed to yield a governing coalition.
"It is time for them to match the courage of their citizens by completing this process," Joe Biden said on Monday, speaking at a gathering of the Veterans of Foreign Wars group in Indianapolis, Indiana.
Despite concerns about a political impasse in the country, Biden said: "I am absolutely confident that Iraq will form a national unity government that will be able to sustain that country."
He acknowledged that "it's difficult. They've never had a government like this before".
Since the Iraqi parliamentary elections in March 2010, no two Iraqi blocs have yet managed to form a governing coalition with the necessary majority.
The vice president's remarks came a week before the scheduled end of the US combat mission in Iraq.
"More than 140,000 troops were in Iraq on inauguration day [on 20 January, 2009] ... by the end of August, 50,000 will remain," Biden said.
"Some said that our draw down would bring about more violence. Well, they were wrong"
Joe Biden, US vice president
US forces in Iraq, which peaked at 176,000, are now at their lowest levels since the 2003 invasion of the country. The remaining troops are shifting into an "advise-train-assist" role until the end of 2011.
"Some said that our draw down would bring about more violence. Well, they were wrong," Biden said.
Concerns have been raised that the US is pulling out of the country too soon, most notably by Lieutenant General Babaker Zebari, Iraq's most-senior army officer, who said that his forces would not be ready to take control of security until 2020.
Zebari predicted that "problems will start after 2011", referring to the Obama administration's deadline for the full withdrawal of US troops from Iraq.
The current political vacuum has added to security concerns with analysts saying that armed groups might exploit the situation to their advantage.
They fear a spike in violence from the anti-government fighters could destabilise the country and undermine state authority.
Barack Obama, the US president, who campaigned for the White House on a pledge to end the Iraq war, plans to make a speech next week about the US troop reduction.
The speech will be given after his return from Massachusetts, where he is vacationing with his family.
The August troop reduction brings to an end the controversial and bloody "Operation Iraqi Freedom" chapter of the war, which began with the US "shock and awe" bombing campaign of Baghdad in March 2003, and saw the US military endure some of the heaviest fighting it had seen for a generation.