The US military said on Monday it had every confidence in the new Iraqi army it is training, after hundreds of Sunni Arab recruits joined a protest at a graduation parade that bordered on mutiny.
Three years to the day since President George W. Bush declared the United States' "mission accomplished" in the brief campaign to invade and overthrow Saddam Hussein, Washington still has 133,000 troops in Iraq, suffering daily casualties.
Bush said on Monday Iraq was now at a "turning point" as Shia Prime Minister-designate Nuri al-Maliki strives, after months of political deadlock, to form a government of national unity that can quell rebellion and sectarian bloodshed.
An as yet unnamed soldier killed by a roadside bomb near Baghdad on Saturday was the 2,400th American to die in uniform in Iraq, all but 140 of them since Bush declared "major combat" over on May 1, 2003. Nearly 17,500 have been wounded.
At least 73 US troops were killed in April, their costliest month since November.
Key to Americans going home, US leaders say, is training Iraqis to take over fighting guerrillas and keeping order - Iraqis like the 978 young men from restive Sunni Arab Anbar province who disrupted a passing out parade on Sunday, some casting off their tunics, and rejected deployment orders.
A spokesman for the US command in Baghdad overseeing a programme that has trained more than 200,000 Iraqi troops, called it an isolated incident and said there was no question of the new soldiers not obeying orders.
"It is important that they are willing and able to deploy around the country," Lieutenant Colonel Michael Negard said of the recruits' complaints that they and their families could be in danger if they were posted away from their hometowns.
It was unclear if any of the unarmed recruits were disciplined after the protest, which ended peacefully.
US forces said they were keen to increase recruitment among the Sunni minority to broaden the sectarian and ethnic mix of the army and win it greater acceptance in places like Anbar, the heartland of the Sunni insurgency.