US Secretary of State Condoleezza Rice met top Iraqi officials in Baghdad today.
Ms Rice first had talks with Shia Islamist Prime Minister Nuri al-Maliki after arriving for her unannounced visit and then met Foreign Minister Hoshiyar Zebari, President Jalal Talabani and Kurdish leader Masoud Barzani.
She arrived as Iraq's parliament passed the first in a series of critical laws aimed at reconciling warring Iraqis.
Washington wants Mr Maliki's splintered government to match recent security gains with progress on political reconciliation between Shias and minority Sunni Arabs.
Bitter sectarian conflict has killed tens of thousands of Iraqis since the US-led invasion in 2003 and threatened to tip Iraq into all-out civil war.
An Iraqi government spokesman said Ms Rice told Mr Maliki that President Bush wants to go ahead with a gradual troop withdrawal of 20,000-30,000 soldiers by the middle of this year.
He added Iraqi forces would be ready to take over security responsibility for all 18 provinces by the end of 2008. The US military has so far handed back seven provinces to Iraq control.