BAGHDAD — Iraq's cabinet today approved a security pact that calls for Americans to withdraw from the country within three years. That action sets up a final vote on the agreement in Iraq's parliament.

Prime Minister Nouri al Maliki built political momentum for the agreement through the weekend, declaring his support and helping persuade leading Shiite Grand Ayatollah Ali al Sistani to give it the green light on Saturday.

Representatives of Maliki's Dawa party framed the deal as a means to end America’s occupation of Iraq while phasing out the assistance coalition forces provide. He reportedly bargained for concessions late last week before endorsing it Friday.

The agreement faces an uncertain outlook in parliament.

Anti-American cleric Muqtada al-Sadr has urged Iraqis to demonstrate against the pact. His delegates on Friday announced they’d form a new resistance, called the Promised Day Brigade, to fight American forces.

“What the Iraqi government has done is a catastrophe because it's giving an authorization that we don’t know when it will end,” said Sadr spokesman Salah al Obeidi

Sunni parties, meanwhile, have indicated they'd prefer to send the agreement before voters as a referendum.

Nonetheless, the agreement won support from 27 of 28 cabinet ministers who voted today. Government spokesman Ali al Dabbagh did not say which minister opposed it. Nine ministers were absent from the vote.

The agreement calls for American forces to pull back from Iraqi cities by June 2009, and for nearly all of them to withdraw from the country by 2011.

Dabbagh stressed that the agreement cannot be modified to extend that timetable.

He highlighted a number of key points, such as:

-- Giving Iraqis control of the International Zone, the compound in central Baghdad that houses U.S. officials and Iraqi government ministries.

-- Requiring American forces to get the consent of Iraq government officials before searching homes or conducting raids.

-- Allowing Iraqis to search all American shipments into the country.

-- Prohibiting American forces from conducting raids in other countries from bases inside Iraq, such as a recent assault on a Syrian location from Iraqi soil.

If the agreement fails in Iraq's parliament, U.S. troops would have no legal framework for being in Iraq unless Iraq seeks an extension of the current United Nations mandate that allows American forces to operate in the country. That mandate expires Dec. 31.

American officials praised the cabinet vote.

“We welcome the cabinet’s approval of the agreement today. This is an important and positive step,” a U.S. embassy spokeswoman said.