Barack Obama visits Iraq 

US Democratic presidential candidate Barack Obama flew to Iraq on Monday to get a first-hand look at security conditions in the country, where violence is at its lowest since early 2004.

His visit thrusts US strategy in Iraq and troop levels to the centre-stage of the November election race between the first-term senator from Illinois and Republican candidate John McCain. There are more than 140,000 US soldiers in Iraq.

Obama has called for the removal of US combat troops within 16 months of taking office should he win the election.

He was expected to meet Iraqi leaders and US commanders, the US embassy in Baghdad said without giving details.

Obama visited Afghanistan over the weekend, the other big foreign policy challenge the next American president will face. Obama called the situation in Afghanistan "precarious and urgent" and said Washington should start planning to transfer more troops there from Iraq.

Iraqi Prime Minister Nuri al-Maliki earlier this month suggested setting a timetable for U.S. troops to leave Iraq, although he has given no dates.

Obama has welcomed Maliki's suggestion but some Iraqis insist the army and police cannot go it alone and that a premature withdrawal of US troops could open the door to the sort of violence that nearly tore Iraq apart not so long ago.

On Sunday the Iraqi government denied Maliki told a German magazine in an interview that he backed Obama's plan to withdraw combat troops within 16 months. The government said Maliki's remarks to Der Spiegel were translated incorrectly.

McCain has attacked Obama for not making a recent visit to get a first-hand look at conditions.

The Republican candidate has been to Iraq eight times while Obama's only other trip was in January 2006, a month before militants blew up a revered Shi'ite shrine in Samarra in an attack that plunged Iraq into vicious sectarian fighting.

The US embassy said Obama, who is visiting Iraq as part of a US congressional delegation, would also meet American troops. Commanders are likely to tell Obama that security gains are fragile and could be jeopardised by a hasty troop drawdown.

Seeking to boost his foreign policy credentials, Obama will travel to other countries in the Middle East and also visit major powers in Europe this week.

He does not have any news conferences scheduled in Iraq.

Obama courted controversy on July 3 when he said he might "refine" his views on withdrawing combat troops from Iraq within 16 months but later said his stance had been unchanged for more than a year and that he intended "to end this war".

McCain says a US troop buildup last year helped boost stability in Iraq and has criticised Democrats' vows for a quick withdrawal as "reckless".

But with violence down dramatically, Baghdad has become increasingly assertive about its own security capabilities.

Indeed, Maliki and President George W. Bush agreed last week to set a "time horizon" for reducing American forces in Iraq.

It was the closest the Bush administration has come to acknowledging the need for a timeframe for US troop cuts. Bush has long opposed deadlines for troop withdrawals.

In a speech last Tuesday, Obama said a "single-minded" focus on Iraq was distracting the United States from other threats, and he promised to shift resources to fighting al Qaeda and the Taliban in Afghanistan.

Bush ordered 30,000 extra troops to Iraq in early 2007 to try to drag the country back from the brink of all-out war between majority Shi'ites and minority Sunni Arabs.

The last of those reinforcements depart Iraq this week, still leaving 140,000 U.S. soldiers in the country, or roughly the same number as when Bush ordered the so-called surge.