For the United States, the Iraq war ended Sunday with whoops of joy as the last convoy of American soldiers rumbled across the border into neighbouring Kuwait.

"No soldiers left there, it's all over," CNN reporter Michael Holmes told CTV News Channel from Camp Virginia, the U.S. base in Kuwait.

"They are relieved," he said of the soldiers he interviewed after they had crossed the border. "There's a degree of pride in what they accomplished. They feel they've done their job."

Holmes said the last 500 soldiers out of Iraq would spend about four or five days in Kuwait before going home. He said the attitude of most was: "Go home and have a beer."

The nine-year war cost almost 4,500 American lives and more than 100,000 Iraqi lives but few agree on what was accomplished.

As the convoy took its five-hour drive to the border, Warrant Officer John Jewell reflected on the country he was leaving behind.

"My heart goes out to the Iraqis," he said. "The innocent always pay the bill."

But once inside Kuwait, the subdued mood changed to one of unbridled joy. The soldiers of the 3rd brigade of the 1st Cavalry Division cheered and pumped their fists in the air. "We're on top of the world!" shouted one soldier from the turret of his vehicle.

"It's just an honour to be able to serve your country and say that you helped close out the war in Iraq," said Specialist Jesse Jones, a 23-year-old who volunteered to be in the last convoy. "Not a lot of people can say that they did huge things like that that will probably be in the history books."

The war began before dawn on March 20, 2003 with a "shock and awe" air bombardment that led to the fall of Saddam Hussein's regime within weeks. But soon the country became torn by sectarian strife as the Shiites and Sunnis fought for control.

While the violence has ebbed recently, the rifts between Sunni and Shiite factions continue. On Sunday, the main Sunni-backed political bloc suspended its participation in parliament to protest the monopoly on government posts by Shiite allies of Prime Minister Nouri al-Maliki.

Back in the U.S., President Barack Obama stopped short of calling the U.S. effort in Iraq a victory in an interview taped Thursday with ABC News' Barbara Walters.

"I would describe our troops as having succeeded in the mission of giving to the Iraqis their country in a way that gives them a chance for a successful future," Obama said.

But no one can predict the future of Iraq, whether it will be able to govern with sectarian violence in the streets and the threat of insurgency.

"We are glad to see the last U.S. soldier leaving the country today. It is an important day in Iraq's history, but the most important thing now is the future of Iraq," said 25-year-old Said Hassan, the owner of a money exchange shop in Baghdad.

"The Americans have left behind them a country that is falling apart and an Iraqi army and security forces that have a long way ahead to be able to defend the nation and the people."

With the departure of the U.S. troops, some Iraqis celebrated the end of what they regarded as a foreign occupation. But others feared the worst was yet to come.

In the northern city of Mosul, there were family parties around cakes inscribed with "congratulations for the end of occupation."

But in the southern city of Basra, Shiite shopowner Karim al-Rubaie said, "Nobody here wants occupation. This withdrawal marks a new stage in Iraq's history." Then he added darkly: "The politicians who are running this country are just a group of thieves."

"These politicians will lead the country into sedition and civil war. Iraq now is like a weak prey among neighbouring beasts."

Just hours after the Americans left, two people were killed and four others wounded when a bomb exploded in a mainly Shiite district of eastern Baghdad.

Iraq's military chief of staff, Lt. Gen. Babaker Zebari said Sunday that his troops were up to the task of uprooting militant groups.

"There are only scattered terrorists hiding here and there and we are seeking intelligence information to eliminate them," Zebari said. "We are confident that there will be no danger."

Still, as CNN reporter Holmes said Sunday, Iraq remains far from peaceful: "It's a place where people die every day."

With files from The Associated Press