WASHINGTON — The leader of one of Iraq’s most powerful Shiite blocs urged Americans yesterday not to fall for “attempts to defame and distort the situation in Iraq” as a pretext for withdrawing troops from the country.

Following a meeting with President Bush in the Oval Office, Abdul Aziz al-Hakim said America’s and Iraq’s futures were linked in Iraq and that no plan to quell the sectarian violence between rival militias should undo the electoral gains that brought his party to power.

“We see the attempts to defame and distort the situation in Iraq not taking into consideration the democratic steps that that country has taken, writing the constitution and establishing a state that depends heavily on the constitution, that it is unified and that it is strong,” Mr. Hakim said. “There are attempts to show the sectarian strife in an attempt to weaken the position in Iraq.”

Mr. Hakim, whom the president yesterday referred to as “his eminence,” is the leader of the Supreme Council for the Islamic Revolution in Iraq, a party that was trained and given sanctuary in Iran in the two decades before the American invasion of Iraq, in 2003. The Badr Brigade, a militia that is affiliated with the party, has carried out revenge killings against Sunnis, though not on the scale of Moqtada al-Sadr’s Mahdi Army.

The meeting with Mr. Hakim is part of the president’s wide-ranging review of Iraq policy, of which he has said the upcoming report from the Iraq Study Group is just one part. That 10-person bipartisan panel — led by a former secretary of state, James Baker, and a former congressman, Lee Hamilton — will release its recommendations for Iraq policy tomorrow. The report is expected to recommend the kind of regional political conference that Mr. Hakim has said his party would reject.

The timing of the meeting also coincides with the deteriorating situation in Iraq. Ten American soldiers have been killed since last weekend. Yesterday, the American ambassador to Iraq, Zalmay Khalilzad, and the chief commanding general in Iraq, George Casey, issued a rare joint statement urging Iraqis not to allow themselves to be used as pawns by saboteurs inside the country seeking to foment further violence.

“Do not allow yourself to be drawn down the road of senseless brutality by striking back,” the message said.

Mr. Bush echoed this line at the White House yesterday. “Part of unifying Iraq is for the elected leaders and society leaders to reject the extremists that are trying to stop the advance of this young democracy,” he said. “I appreciated very much his eminence’s strong position against the murder of innocent life.”

At a press conference at the U.S. Institute of Peace yesterday after his meeting with Mr. Bush, Mr. Hakim denied that the Badr Brigade existed at all and said that since 2003, it had been transformed into the “Badr Organization.” Mr. Hakim also complained that coalition forces in Iraq had not hit Sunni insurgents hard enough.

Mr. Bush is expected to meet with Iraq’s Sunni Arab vice president, Tariq al-Hashim, in January.

[As reported by the Associated Press, some consider Mr. Hakim a more powerful political figure than Prime Minister al-Maliki.

Mr. Hakim’s meeting with the president was evidence that Mr. Bush, under pressure to find a new blueprint for his war strategy, was getting more personally involved in the political infighting among Shiites, Sunnis, and Kurds.

“I told him that we’re not satisfied with the pace of progress in Iraq and that we want to continue to work with the sovereign government of Iraq,” Mr. Bush said. He said the young Iraqi government needs to be given more capability as quickly as possible to secure the country from extremists and murderers.

Before Mr. Hakim’s visit to America, two Maliki aides and a third person close to Mr. Hakim said the cleric was expected to try to persuade Mr. Bush to enlist Iran’s help in quelling violence in Iraq.

Mr. Bush spoke with Mr. Hakim directly about Iran and Syria and the critical need for them to respect Iraqi sovereignty and stop destructive activity that undermines Iraq’s unity government, a senior administration official said.

He spoke on condition of anonymity because he was not authorized to divulge details of the meeting.]