In a television interview on Saturday, al-Maliki said he would also carry out a change in the "ministerial structure", but did not elaborate.
Shia officials have said al-Maliki's government could collapse if US-backed Baghdad security plan fails to put a brake on sectarian violence.
Sadr City raid
Meanwhile, hundreds of US soldiers entered the Shia dominated Sadr City on Sunday in the first major push into the area since the Baghdad security crackdown began last month.
Soldiers conducted house-to-house searches, but met no resistance in the district, according to Lieutenant-Colonel David Oclander.
Sadr City is thought of as firmly in the hands of the al-Madhi Army, a group led by Muqtada al-Sadr, a Shia leader
Also on Sunday, US troops arrested three people and wounded a female bystander in a raid on a mosque in Baghdad, a military spokesman said.
It has been unusual for US soldiers to enter Iraqi mosques. In most cases, Iraqi security forces search places of worship while US forces remain outside.
"Coalition force's soldiers respect the sanctity and holiness of all places of worship," said Lieutenant- Colonel Chris Garver, a US spokesman.
He said the raid had been carried out because a "suspected terrorist" was known to be inside.
The target and two alleged accomplices were arrested in the raid.
"Mosque entries occur only as a last resort, and only when substantial and credible evidence shows insurgent activity is occurring there," said Garver.
During the operation an Iraqi woman was wounded in the thigh and head, a US military statement said.
Elsewhere in Baghdad, an Iraqi journalist was shot dead outside his home in a Sunni neighbourhood on Sunday.
Mohan al-Dhaher, a senior editor at the independent al-Mashriq daily newspaper, had just left his house to go to work when gunmen in two vehicles pulled up and tried to kidnap him, neighbours and colleagues said.
Al-Dhaher, who was married with four children, was shot dead by the gunmen when he tried to resist, neighbours said.
The body of another local journalist, Jamal al-Zubeidi, editor-in-chief of the al-Safeer newspaper, was found last week in a Shia area of Baghdad, a local journalists' association said.
It said al-Zubeidi was kidnapped on February 24 from central Baghdad.