The US mission in Iraq -- the biggest in the world -- will slash its numbers by two-thirds by the end of this year from its peak figure of over 16,000, the American ambassador to Baghdad said.

Overall staffing levels at the US's embassy in Baghdad and its consulates in the southern port city of Basra, the Kurdish regional capital of Arbil and the disputed northern city of Kirkuk, will drop to around 5,500, including contractors, by the end of the year.

"A year ago, we were well above 16,000, now we're at 10,500," Ambassador Stephen Beecroft told reporters. "By the end of this year, we'll be at 5,500, including contractors."

"The diplomatic presence is down below a thousand."

The American embassy had swelled in size due to the departure from Iraq of US forces in December 2011, because planners believed the diplomatic mission would have to take on a wide array of responsibilities left by the military.

As time has gone on, however, the embassy has handed over multiple sites to the Iraqi government and reduced the number of diplomats working in Iraq.

All US troops except for a small number under US embassy authority left Iraq at the end of 2011.

Obama hails US troops on Iraq war anniversary
Washington (AFP) March 19, 2013 - US President Barack Obama marked the tenth anniversary of the Iraq invasion on Tuesday by paying tribute to the "sacrifice" of US troops, but had few words for the Iraqi people.

In a muted statement, issued on the eve of a visit to a Middle East much changed since his predecessor George W. Bush unleashed the 2003 war, Obama promised to support wounded American veterans of the conflict.

"As we mark the 10th anniversary of the beginning of the Iraq war, Michelle and I join our fellow Americans in paying tribute to all who served and sacrificed in one of our nation's longest wars," Obama said.

The last US troops left Iraq in December 2011, eight years after they had deposed dictator Saddam Hussein. They left behind an elected Iraqi government, but a population scarred by what is a still ongoing period of violence.

Around 4,500 US troops died in the conflict, and many more were wounded, while at least 112,000 Iraqi civilians have lost their lives, some caught up in fighting and others murdered by sectarian death squads or killed in bomb attacks.

"We salute the courage and resolve of more than 1.5 million service members and civilians who during multiple tours wrote one of the most extraordinary chapters in military service," Obama said.

"We honor the memory of the nearly 4,500 Americans who made the ultimate sacrifice to give the Iraqi people an opportunity to forge their own future after many years of hardship," he added.

The statement did not touch on the Bush administration's decision to start the war, which Obama had opposed at the time, but instead underlined the grim aftermath faced by US veterans and the families of the dead and wounded.

"We must ensure that the more than 30,000 Americans wounded in Iraq receive the care and benefits they deserve and that we continue to improve treatment for traumatic brain injury and post-traumatic stress disorder," Obama said.

The United States still has more than 60,000 troops deployed in Afghanistan 12 years after the September 11 attacks by the Al-Qaeda network on US cities, but Obama has vowed to bring them home by the end of next year.

On Tuesday, Obama is due in Israel, where he will hold talks with Israeli leaders about the current crises in the Middle East: the civil war in Syria and the West's stand-off with Iran over its nuclear program.