Iraqi Prime Minister Nouri Maliki has said Iraqi forces will take over control of the country's security from foreign forces by the end of the year.
Iraqi troops have already taken control of four provinces
Mr Maliki's announcement came hours before some 157 were killed in a car bomb blast in Iraq's capital, Baghdad.
The attack on a food market left scores of people injured.
Car and suicide bombings have occurred almost daily in Baghdad in recent months, despite a US-led security crackdown since February.
The parliament bloc loyal to radical cleric Moqtada Sadr withdrew from the cabinet Monday, demanding Mr Maliki set a timetable for US troop withdrawal.
On Wednesday, Iraqi troops took control of security in the southern province of Maysan - the fourth of 18 provinces to come under full Iraqi security control since the 2003 US-led invasion.
In a speech at a ceremony marking the handover, Mr Maliki was quoted as saying that three provinces in the autonomous Kurdistan region would be next, followed by Karbala and Wasit provinces.
"Then it would be province by province until a full transfer had been completed by the end of the year," Mr Maliki was quoted as saying in the speech, delivered by National Security Adviser Mowaffaq al-Rubaie.