Iraqi and U.S. authorities freed 495 prisoners from U.S. facilities on Saturday, completing a mass release announced by the prime minister earlier this month as part of his national reconciliation efforts.
U.S. Ambassador Zalmay Khalilzad welcomed the move and said more prisoners could be freed.
"We are prepared in consultation with the Iraqi leaders to make future prisoner releases and to take other concrete steps to facilitate reconciliation," he said in a statement. "As the government moves forward with these steps, it can count on support from the U.S. government."
Al-Maliki had promised to release 2,500 inmates by the end of the month.
The Justice Ministry said Saturday's releases fulfilled that promise but stressed officials would continue to study the cases of individual inmates and release them as merited.
The U.S. military has not provided a sectarian breakdown of those being released, but most were believed to be Sunnis, the minority that was dominant under ousted leader Saddam Hussein but lost power when he was ousted. Sunnis frequently complain of random detentions and maltreatment at the hands of the Shiite-led government and the prisoner releases are seen as a key step toward soothing that anger and dampening the Sunni-led insurgency.
"The new government is reaching out not only to all Iraqis but also to its neighbors," the ambassador said. "We expect these visits to be successful, as the countries that Mr. Maliki is visiting understand what happens in Iraq will affect the stability of the area and shape the future of the region."
Khalilzad urged insurgents to respond to al-Maliki's overture by laying down their arms and joining in the reconstruction of Iraq.