A meeting between U.S. President George W. Bush and Iraq's prime minister was postponed by a day just as leaked documents revealed a senior White House adviser's doubts about Nouri al-Maliki's ability to quell rising sectarian violence.

On Wednesday, Bush flew from a NATO summit in Latvia for a two-day summit with al-Maliki in Amman, Jordan. The president was expected to ask al-Maliki how best to train Iraqi forces quickly, so they can take more responsibility for halting the bloodshed between Sunni and Shia Muslims.

The two leaders were due to have dinner with Jordan's King Abdullah, but the White House announced the postponement, saying Bush and al-Maliki would instead meet Thursday.

A top Iraqi legislator said the tri-nation meeting was cancelled at the request of the Iraqis, who did not want the Jordanian king present.

Redha Jawad Taqi, a senior aide of top Shia politician Abdul-Aziz al-Hakim who also was in Amman, said the Iraqis balked at the three-way meeting after learning that King Abdullah wanted to broaden the talks to include the Israeli-Palestinian conflict.

The meeting's delay comes following some of the worst violence in Iraq since the U.S.-led invasion of 2003. 

In all, 15 civilians and 13 insurgents were killed in violence around Iraq on Wednesday, police and U.S. officials said. A total of 52 bullet-riddled bodies, some of them bound and blindfolded and bearing signs of torture, were found in various locations around Baghdad, according to officials of the Interior Ministry. 

In addition, the U.S. military announced the deaths of two more American soldiers.

The planned meeting has already sparked more division in al-Maliki's fragile coalition government, as lawmakers and cabinet ministers loyal to Shia cleric Muqtada al-Sadr suspended their participation in the parliament and government to protest the summit.

Memo expresses doubts over leader

The White House has avoided saying that Bush will be pressuring al-Maliki to do more to stop the violence.

National security adviser Stephen Hadley said Bush would be listening to al-Maliki's ideas, not imposing plans on him.

But in a classified Nov. 8 memo following his Oct. 30 trip to Baghdad, Hadley expressed doubts about whether al-Maliki had the capacity to control the daily sectarian attacks, and recommended steps to strengthen the Iraqi leader's position, the New York Times reported Wednesday.

"The reality on the streets of Baghdad suggests Maliki is either ignorant of what is going on, misrepresenting his intentions, or that his capabilities are not yet sufficient to turn his good intentions into action," the memo said.

There is a sense of urgency surrounding the meeting because U.S. officials finally recognize Iraq is falling apart, said David Phillips, a former senior adviser to the U.S. State Department and a strong critic of the reconstruction effort.

"There's no success strategy that President Bush can pull out of his hat," Phillips told CBC News on Tuesday about the summit.

He said he believes the White House committed a grave policy error by not handing over control to the Iraqis immediately after the removal of Saddam Hussein.

"There's been little progress, just enormous death and destruction," he said. "Three years later and we've come full circle."

Despite considerable pressure at home to change the U.S. strategy in Iraq, Bush said Tuesday that the U.S. would not pull its forces out of the country "before the mission is complete."

Lawmakers protest

Meanwhile, a statement from the 30 Iraqi lawmakers and six cabinet ministers said the meeting constituted a "provocation to the feelings of the Iraqi people and a violation of their constitutional rights." The statement did not explain that claim.

The support of the bloc of al-Sadr loyalists in the 275-member parliament was crucial to al-Maliki's election as prime minister this year, a fact that many see reflected in his reluctance to take action against the Mahdi Army, a militia loyal to al-Sadr and known to be behind much of the sectarian violence in Iraq.

Disbanding Shia militias such as the Mahdi Army and Badr Brigade, which also is linked to a major Shia political party, has been a key demand as the Bush administration looks for ways to contain the violence in Iraq and win over Sunni Arabs, who make up the bulk of the three-year-old insurgency.

In Amman, about 300 people carrying Jordanian flags and anti-Bush banners marched through the University of Jordan to protest the president's visit. Security was increased around the capital, with tanks and machine-gun-toting soldiers dotting the main road from the airport.

With files from the Associated Press