Iraq's parliament has delayed a vote on a security pact with the United States that would allow American forces to stay through 2011 under tight Iraqi supervision.

Mahmoud al-Mashhadani, speaker of the parliament, made the remark on Wednesday.

''The leaders have agreed to all points except one. The blocs informed us that they are in need of time to settle this point. Therefore we declare today that the session is adjourned till tomorrow at 10 am."

The proposed deal meets a longtime Iraqi demand for a clear timetable for the exit of some 150-thousand US troops after years of war.

Under the deal, US forces will withdraw from Iraqi cities by June 30 and the entire country by January 1, 2012.

The Shiite-led government was struggling to meet the demands of political blocs, including a large group of Sunni Arab lawmakers, seeking concessions in return for supporting the agreement.

Prime Minister Nouri Al-Maliki's ruling coalition appears to be assured of at least a slim majority in the 275-seat legislature.

But he is seeking a bigger win that transcends Iraq's factionalism and sectarian divisions and reinforces the legitimacy of the pact. The pact could lead to full Iraqi sovereignty and close the bloody chapter that began with the US-led invasion in 2003.