Iraqi Prime Minister Nuri al-Maliki arrived in Washington on Sunday, looking to open a new chapter with the United States after a protracted war that left deep wounds.
Maliki was later expected at a dinner reception with top US diplomat Hillary Clinton.
He officially kicks off his two-day visit by holding wide-ranging talks with President Barack Obama at the White House on Monday, less than a month before the complete withdrawal of US troops from Iraq and more than eight years after the launch of the US-led invasion that ousted Saddam Hussein.
Maliki is also due to meet with Vice President Joe Biden and lawmakers to discuss security, energy, education and justice.
The US and Iraqi leaders "will hold talks on the removal of US military forces from Iraq, and our efforts to start a new chapter in the comprehensive strategic partnership between the United States and Iraq," the White House said.
The meeting comes as Iraq's top security adviser said that NATO will mirror the nearly-complete pullout of US forces by withdrawing its Iraq training mission at year's end after Baghdad refused to grant it legal immunity.
But an official at NATO headquarters in Brussels denied that any decision had been taken. "When they ask us to extend the mission, we need to see that the same legal framework will extend as well," the official said on condition of anonymity.
Iraq said the end of the mission was a surprise, with NATO previously having agreed in principle to staying through to the end of 2013.
"We are sorry that NATO has advised that it will withdraw its mission from Iraq... because immunity is something that is out of the government's reach," National Security Adviser Falah al-Fayadh said in an interview aboard a flight transporting Prime Minister Nuri al-Maliki to Washington.
He said Baghdad was informed of the decision on Thursday.
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The failure to agree on immunity from prosecution closely mirrors Iraq's refusal to grant US soldiers similar protections earlier this year, sinking a potential deal between the two countries that means all American soldiers left in Iraq will leave by December 31.
Around 6,000 US troops remain stationed in the country 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 Khayrullah Hassan Babakir, Trade Minister Hadi al-Ameri 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.
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. It was not immediately clear whether Maliki would attend the speech.
Facing a reelection battle in November, Obama is expected to stress he has kept his 2008 campaign promise to bring American troops home from Iraq.
But although violence has declined markedly from the sectarian bloodbath that marked 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.