Nouri Maliki has given up his post as Iraq's prime minister to Haider Abadi, state television reported today - a move which could end a political deadlock that plunged Baghdad into uncertainty as the country fights a Sunni militant insurgency.
The Iraqiya television network said Mr Maliki has "relinquished the post of prime minister" but did not elaborate. Afak television, Mr Maliki's private network, ran a bulletin saying "Maliki joins the greatest men of history by giving up posts".
The announcement comes ahead of an address Mr Maliki is due to make later, according to the government.
On Monday, Iraq's President Fouad Massoum named Mr Abadi to form the next government, but Mr Maliki had until now refused to step aside.
Mr Maliki has been struggling for weeks to stay for a third four-year term as premier amid an attempt by opponents to push him out, accusing him of monopolising power and pursuing a fiercely pro-Shiite agenda which has alienated the Sunni minority.
But in a meeting of his Dawa party tonight, Mr Maliki agreed to endorse Mr Abadi as the next prime minister, two senior members of his State of Law parliamentary bloc - Hussein al-Maliki and Khalaf Abdul-Samad - told the Associated Press.
They and two other Shiite politicians said Mr Maliki would announce his endorsement in his speech.
The politicians said Mr Maliki also agreed to drop a lawsuit in the constitutional court challenging Mr Abadi's nomination.
The pressure intensified this week when his Shiite political alliance backed Mr Abadi to replace him, and President Massoum nominated Mr Abadi to form the next government. Mr Maliki has been refusing to step aside, saying the nomination violates the constitution.
Mr Maliki had grown increasingly isolated as not only erstwhile Shiite allies but also top ally Iran, the United States and the UN backed Mr Abadi, who has 30 days to put together a Cabinet for Parliament's approval.
The UN Security Council urged Mr Abadi to work swiftly to form "an inclusive government that represents all segments of the Iraqi population and that contributes to finding a viable and sustainable solution to the country's current challenges".
The US and other countries have been pushing for an inclusive government that will ease anger among Sunnis, who felt marginalised by Mr Maliki's administration, helping fuel the dramatic sweep by the Islamic State extremist group over much of northern and western Iraq since June.
The extremist Islamic State group's lightning advance across much of northern and western Iraq has driven hundreds of thousands of people from their homes since June, and last week prompted the US to launch aid operations and air strikes as the militants threatened religious minorities and the largely autonomous Kurdish region.
Yesterday, the UN declared the situation in Iraq a "Level 3 emergency" - a development that will allow for additional assets to respond to the needs of the displaced, said UN special representative Nickolay Mladenov, pointing to the "scale and complexity of the current humanitarian catastrophe".
The UN move came after some 45,000 people, members of the Yazidi religious minority, were able to escape from a remote desert mountaintop where they had been encircled by Islamic State fighters, who view them as apostates and had vowed to kill any who did not convert to Islam.
They were able to reach safety after Kurdish fighters from neighbouring Syria opened an exit corridor. US and Iraqi forces had earlier airlifted aid to those trapped.
US officials said today that roughly 4,500 people remain on Sinjar Mountain, nearly half of whom are herders who lived there before the siege and have no desire to leave.
The UN said it would provide increased support to the Yazidis and to 400,000 other Iraqis who have fled since June to the Kurdish province of Dahuk. A total of 1.5 million people have been displaced by the fighting.
The United States has been carrying out air strikes in recent days against Islamic State fighters, helping fend back their advance on Kurdish regions.
French President Francois Hollande confirmed today the "imminent delivery of military equipment" to Kurdish forces in a phone call with new Iraqi president Mr Massoum, Mr Hollande's office said. It did not specify the type or amount of equipment.
The statement said Paris would also provide more humanitarian aid. France has sent dozens of tons of aid in several deliveries this week.
In western Iraq, fighting erupted early today in the militant-held city of Fallujah, about 40 miles (65km) west of Baghdad. The clashes on the city's northern outskirts killed four children, along with a woman and at least 10 militants, said Fallujah hospital director Ahmed Shami.
He had no further details on the clashes, beyond saying that four other children and another woman were wounded in the violence.
It was difficult to gauge the situation in Fallujah, which has been in the hands of the Islamic State and allied militants since early January, when the insurgents seized much of the western Anbar province along with parts of the provincial capital, Ramadi.
Meanwhile, eight civilians were killed in separate attacks across Baghdad today.
A bomb attached to a minibus in the central Sheik Omar area killed four commuters and wounded 11 others, a police officer said. Another bomb went off in a commercial area in the south-eastern Bayaa neighbourhood, killing two and wounding nine, another police officer said.
Two other civilians were killed and 11 wounded when two mortar rounds struck another residential area, he said.
Three medical officials confirmed the casualty figures.
The White House commended Mr Maliki for stepping aside.
President Barack Obama's national security adviser Susan Rice expressed hope that the power shift "can set Iraq on a new path and unite its people" against the security threat from IS.
She also said the United States remained committed to a strong partnership with Iraq and its people.