Iraqi leaders hope to work out a deal to end sectarian violence when they meet again today.
They met yesterday and announced a four-point plan, drafted under US pressure, to end violence.
Washington's ambassador and its top general in Iraq issued a statement welcoming Prime Minister Nuri al-Maliki's move as "a significant step in the right direction.
"Now begins the hard work of implementing the plan," they added.
Mass kidnaps by men in uniform and dozens of murders have fuelled fears in Iraq of all-out sectarian civil war.
Shia and Sunni political leaders admitted there was still much to agree, and several seemed at odds in their interpretations of what was announced by Mr Maliki after two days of talks culminating in a deal late last night.
The formation of local security committees for Baghdad is the plan's first point. They should involve politicians, tribal and religious figures and the Iraqi military. But several officials said they did not know how large an area each panel would cover, the size of the committees or their powers.
The second point of the plan was a Central Committee for Peace and Security that would co-ordinate among the local groups and with the military.
The third element would be new supervision of the media and the fourth would be monthly reviews of the plan.
US officials are uneasy that Mr Maliki's unity cabinet has yet to act after four months to rein in party militias and other groups behind violence, such as two mass kidnaps this week.