BAGHDAD  - Iraq's new government said Tuesday that it would release 2,500 detainees, nearly 10 percent of those held in Iraqi and American detention centers, and said that it would adopt a "national reconciliation" plan to reintegrate former members of Saddam Hussein's ruling Baath Party into society.

Prime Minister Nouri al-Maliki said the first 500 detainees would be released Wednesday, with others following in the next few days.

A U.S. military spokesman said the decision to free the detainees, the largest group to be released in the 38 months since the U.S.-led invasion, had been agreed upon in a joint review by Iraqi and American officials. He said those freed would not include any deemed "guilty of serious crimes such as bombings, torture, kidnapping and murder."

Al-Maliki, in his third week in office, gave few details of the reconciliation program. But he compared it to South Africa's "truth and reconciliation" process in the 1990s, which, he said, "sent some criminals to the courts and reinstated other people in society after promising not to try and rebuild" the country's apartheid system. The Iraqi leader said his government's plan, like South Africa's, would involve a national commission, and others in Iraq's 18 provinces, that would work to "an agreed timetable and program."

At a news conference in Baghdad, the prime minister drove home the carrot-and-stick approach he outlined in a visit last week to the southern oil city of Basra. There, he vowed to use "an iron fist" to crush Sunni insurgents and sectarian militias terrorizing Basra but promised that his government would rule in ways that would make a priority of rebuilding Iraq on the basis of justice for the communities of Shiites, Sunnis and Kurds now engaged in a bitter struggle for economic and political power.

On Tuesday, al-Maliki's focus was on the Sunni minority that was the mainstay of Hussein's rule.

"We are ready to turn a new page with those who so desire it, and we will respond with force to those who want to pursue violence," he said. "Those who want to end the bitterness of the past have the way open through the process of national reconciliation, but those who choose bloodshed will find us ready to deal with them."

The detainee release, though sweeping, seemed likely to fall far short of the demands of Sunni politicians who have joined in the uneasy partnership with the dominant Shiites in the new government, the first with a full, four-year tenure since Hussein's overthrow. Iraq's Interior Ministry said Tuesday that 27,800 people are being held in Iraqi and American prisons across the country--a figure that includes criminals and former Baathists as well as insurgents and members of their support network.

A spokesman for the U.S. military command, Lt. Col. Kevin Curry, said there were about 14,500 detainees in the detention centers run by the American-led coalition, including several thousand at Abu Ghraib prison outside Baghdad.

Curry said the terms of the detainees' release included a pledge to renounce violence "and to be good citizens of Iraq." He added, "All of these detainees selected for release have been found to be relatively low threats."

Similar pledges have been made by other detainees released since Iraq resumed sovereignty after the formal period of American occupation ended two years ago, including a group of nearly 1,000 men who were freed from Abu Ghraib in August. Some of those have since been killed in clashes with American and Iraqi troops or rearrested on suspicion of involvement in the insurgency. The August release was ordered as a concession to Sunni leaders then engaged in tense negotiations with Shiite and Kurdish leaders over Iraq's new constitution.