United States Vice President Joe Biden arrived in Iraq on Monday to commemorate the official end of the US combat mission the following day, dpa reported.
Biden is also to meet with Iraq's main parties to discuss the political impasse in the country, as Baghdad has been unable to form a new government since the March 7 election.
This is the vice president's sixth trip to the country since 2009 and he was greeted at the airport by Iraqi Foreign Minister Hoshyar Zebari.
During a July visit, Biden urged the rival political blocs to bring stability to the country and work out their differences, though officials said he did not give concrete proposals and only offered his advice.
The vice president would again meet with the leaders of the main factions, including Prime Minister Nuri al-Malaki and former premier Iyad al-Allawi, with whom he sat during his last trip.
He was also expected to see Iraqi President Jalal Talabani, a Kurdish leader, and representatives of other factions and ethnic and religious groups in the country.
Talks between al-Malaki and al-Allawi remain in disarray amid disagreement over whose party should head the new government, while deadly attacks are on the rise in the country, with insurgents targeting both civilians and security forces.
The departing commander of American forces in Iraq, General Ray Odierno said this week that he was concerned about the future of the country and Iraqis' trust in government if the political horse- trading does not end soon.
"What I don't want is for them to lose faith in the system, the democratic system, and that's the long-term risk, do they lose faith in the process," Odierno told The New York Times.
Odierno transfers his command to Lt Gen Lloyd Austin on Wednesday.
The US soldiers and Iraqis will first hear a planned speech from President Barack Obama in Washington late Tuesday, at the end of official combat operations.
Some 49,700 troops are left in the country - the lowest number since the invasion in 2003 - and are set to focus on advisory, counter terrorism and training roles. Most of the departing US troops have already left Iraq. Their new mission will be called "New Dawn."
Despite tighter security measures being imposed on the capital by Iraqi forces as the draw-down came to a close, one civilian was killed and three injured by a so-called "sticky bomb," an explosive attached to a car, in northern Baghdad.
New checkpoints, increased spot checks and a general increase in the number of troops on foot patrol were visible in markets and on the main streets of Baghdad, witnesses said.
"The security forces are capable of protecting the country after the withdrawal of the US troops," said General Qasim Atta, a spokesman for the Iraqi military.
He also said Iraqi intelligence units were launching campaigns to counter attacks allegedly being planned by al-Qaeda linked organizations.
Last week, Prime Minister Nuri al-Maliki put the country on high alert and warned that insurgents could mount attacks in the days around August 31, the final official day of US combat operations.
In recent weeks, car bomb blasts and attacks on police officers have occurred in larger numbers, and July was the deadliest month in two years.
A full withdrawal of the last US troops is planned for 2011.
At the height of the war, there were more than 160,000 US troops in Iraq.