President Barack Obama vowed Monday that Iraq had "an enduring partner" in the United States after meeting Iraqi Prime Minister Nuri al-Maliki as America marks its exit from a nine-year war launched to oust Saddam Hussein.

"After nearly nine years, our war in Iraq ends this month," Obama said after meeting with Maliki at the White House.

"In coming days, the last American soldiers will cross the border out of Iraq with honor, and with their heads held high," he added, although he said "history will judge" the decision by his predecessor president George W. Bush to invade Iraq in 2003.

Acknowledging a conflict which has left a wounding legacy for both nations, Obama said the men were there "to honor the sacrifices of all those who made this day possible and to turn the page."

The two men were later to visit Arlington National Cemetery where many of the nearly 4,500 US war dead lie buried.

Tens of thousands of Iraqis also died in a war, insurgency and sectarian violence that left Iraq with the stirrings of a democratic political system but facing challenges from neighbor Iran.

Obama added "it was time to begin a new chapter in the history between our countries. A normal relationship between sovereign nations. An equal partnership based on mutual interests and mutual respect.

"As we end this war, and as Iraq faces its future, the Iraqi people must know that you will not stand alone. You have a strong and enduring partner in the United States of America," the US leader said.

Maliki thanked Obama and said his country now had "very high aspirations," saying Iraq had established a democratic process and could now rely on its own security forces.

The last US troops of a garrison that once numbered nearly 170,000 are preparing to leave this month, ending a nearly nine-year presence following the US invasion.

Maliki will also see Vice President Joe Biden and lawmakers to discuss security, energy, education and justice.

The full withdrawal from Iraq was mandated under an agreement concluded by the former administration of President George W. Bush.

Long-running talks designed to provide for a future US training mission by US troops failed over the issue of providing immunity for US troops in Iraq, though both sides say they are still talking about future military exchanges.

Around 6,000 US troops remain stationed in Iraq on three bases, down from peaks of nearly 170,000 soldiers and 505 bases. All the troops must leave by the end of the month.

For his third visit to the United States since coming to power in May 2006, Maliki is being accompanied by Foreign Minister Hoshyar Zebari, Culture Minister and acting Defense Minister Saadun al-Dulaimi, Transport Minister Hadi al-Ameri, Trade Minister Khayrullah Hassan Babakir and National Security Adviser Falah al-Fayadh.

Also on the trip are National Investment Commission chief Sami al-Araji and Maliki's chief adviser and former oil minister Thamer al-Ghadban.

With American troops on their way out, some Republican lawmakers have expressed concern that neighboring Iran could step into the security vacuum.

But Obama warned that other nations "must not interfere in Iraq."

The US military leaves behind an Iraqi security force with more than 900,000 troops, which US and Iraqi officials assess is capable of maintaining internal security but cannot defend the country's borders, airspace or maritime territory.

Some 157 uniformed US soldiers and up to 763 civilian contractors will remain to help train Iraqi forces under the authority of the sprawling US embassy in Baghdad.

Obama will mark the final withdrawal of all US troops from Iraq by addressing returning soldiers on Wednesday at a base in North Carolina.

Facing a reelection battle in November, Obama stressed he has kept his 2008 campaign promise to bring American troops home from Iraq and is now turning to nation building at home in tough economic times.

Although violence has declined markedly from the sectarian bloodbath that reached a peak in 2006-2007 when tens of thousands were left dead, it remains a common feature of modern Iraq. In November alone, 187 people were killed in attacks, and several major bombings took place this month.