US President Barack Obama arrived in Iraq on Tuesday on his first visit since taking office three months ago, as the war-torn country wrestles with a new upturn in deadly attacks.

Obama flew into Baghdad from Turkey aboard Air Force One on the latest leg of a week-long tour to Europe and the Middle East and was immediately rushed off to meet General Ray Odierno, the top US army commander in Iraq.

He was expected to hold telephone talks with his Iraqi counterpart Jalal Talabani and Prime Minister Nuri al-Maliki and to present medals to American soldiers during the surprise visit.

Poor weather scuppered Obama's plans to meet the Iraqi leaders in person, a White House spokesman said, noting that the president had chosen to visit Iraq rather than Afghanistan because of its close proximity to Turkey.

"Our men and women who are in harm's way, either in Iraq or Afghanistan, deserve our utmost respect and appreciation," the spokesman said.

Obama, who opposed the 2003 invasion of Iraq ordered by his predecessor George W. Bush, has used his debut overseas tour to reach out to the Islamic world and attempt to restore America's battered image abroad.

Although it was his first trip to Iraq as president, Obama visited the country last year when he was a candidate for the White House.

In February, Obama announced a new strategy that will see most combat troops withdraw from Iraq by August 2010, although a force of up to 50 000 will remain until the end of the following year.

A military accord signed between Baghdad and Washington in November requires all US troops to leave the country by the end of 2011.

Ending the war which sparked an insurgency that cost thousands of lives would mark a new era of US diplomacy in the Middle East including "principled and sustained engagement" with Iraq's neighbours Iran and Syria, Obama has said.

Violence in Iraq has fallen dramatically since Sunni tribal leaders allied with US forces against al-Qaeda extremists in late 2006 and as more American troops poured into Iraq under then president Bush's "surge" strategy.

But the last few weeks have witnessed a rise in violence that has seen dozens of civilians killed and hundreds wounded.

A string of car bombings in mainly Shiite districts of Baghdad on Monday killed at least 34 people in what the US military said appeared to be coordinated attacks by al-Qaeda, and another eight were killed in another attack in the capital before Obama's arrival on Tuesday.

Monday's blasts recalled the blackest days of post-Saddam Hussein violence in the capital and shattered the city's fragile security situation.

Maliki blamed the attacks on al-Qaeda and supporters of the banned Baath party of the toppled dictator.

"The supporters of this bad system, in cohorts with al-Qaeda, have sowed death in our beloved city of Baghdad," he said. "These attacks unveil the bloodthirsty face of this party."

The attacks came about a week after deadly clashes in Baghdad between Iraqi troops and former Sunni insurgents now turned anti-Qaeda militants over the arrest of their leader on criminal charges.

The US military, however, ruled out the any involvement of disaffected Sahwa (Awakening) members, and also laid the blame on al-Qaeda in Iraq.

Bush was the last US president to visit Iraq in a trip that was overshadowed by an Iraqi journalist who hurled his shoes at him to protest the March 2003 US-led invasion that toppled Saddam.

TV reporter Muntazer al-Zaidi soared to global fame and was seen as hero in much of the Arab world for his farewell gesture to a deeply unpopular president.

He was jailed last month for three years by a Baghdad court, a sentence that was on Tuesday cut to one year by an appeals tribunal.