Mahmoud al-Mashhadani was speaking on Saturday at a UN-sponsored conference on transitional justice and reconciliation in Baghdad.
"Just get your hands off Iraq and the Iraqi people and Muslim countries, and everything will be all right," he said in a speech as the conference opened.
"What has been done in Iraq is a kind of butchery of the Iraqi people."
He also criticised US support for Israeli attacks against Lebanon.
The two-day conference, which was originally supposed to be opened by Nuri al-Maliki, the Iraqi prime minister, will address the issue of dealing with the crimes of previous regimes and a plan to reconcile warring factions.
The prime minister is expected to name a reconciliation committee on Saturday.
Al-Mashhadani told the audience of UN officials, foreign experts, Iraqi politicians and civil society representatives that the Iraqi people had little use for foreign advice on running the country or for foreign-sponsored conferences.
"If a reconciliation project is going to work it has to talk to all the people," he said. "It must go through our Iraqi beliefs and perceptions. What we need is reconciliation between Iraqis only, there can be no third party."
He related an anecdote about how American soldiers keep people waiting in lines at checkpoints for hours because they insist on resting their bomb-sniffing dogs.
"The sleep of American dogs is more important than people being stopped in the street for hours," he said.
The UN representative who then opened the conference referred to al-Mashhadani's speech as "spirited".
More US troops
Meanwhile on Saturday, the US moved to bolster American troop strength in Baghdad to cope with the escalating violence as seven Shia workers were shot dead in west Baghdad and explosions in the heart of the capital shattered a one-day calm after a ban on private vehicles expired.
The seven Shia died in a drive-by shooting at noon in the Furat neighbourhood near Baghdad airport, police Lieutenant Maitham Abdul-Razzaq said. Two other workers were wounded.
Violence resumed after a one-day
ban on Baghdad vehicles expired
Earlier, two large explosions occurred in eastern Baghdad about 20 minutes apart at midmorning. One targeted an Iraqi police patrol, but killed a civilian. The other occurred near the Rasheed military camp, killing an American soldier.
A ban on private vehicles had kept down violence on Friday after one of the most violent weeks in the capital this year.
It expired on Friday evening, and within hours, heavy bursts of automatic weapons rang out.
A senior US defence official said the Pentagon was moving ahead with scheduled deployments to Iraq next month and was moving one battalion to Baghdad from Kuwait, where it was in reserve.