Top US officials warned Iraq's leader against "sectarian" policies as President Barack Obama Thursday weighed calls for air strikes on Sunni insurgents bearing down on Baghdad.
The sharp criticism of Prime Minister Nuri al-Maliki came as he scrambled to beat off a militant onslaught that has seen an entire province and parts of three others fall out of government control in an offensive that could threaten the country's very existence.
The swift advance of fighters led by the Islamic State of Iraq and the Levant (ISIL) has sparked international alarm and the United Nations has warned that the crisis was "life-threatening for Iraq".
Hundreds of thousands of Iraqis have been displaced in the nine days of fighting and an unknown number killed, while dozens of Indians and Turks have been kidnapped.
Baghdad has formally requested Washington to launch air strikes on the advancing militants, but there were no signs US military action was imminent.
- US officials castigate Maliki -
Instead US officials castigated Maliki, who is being blamed in Washington for causing Iraq to splinter after discriminating against the minority Sunni community.
Vice President Joe Biden drove home the US message that Maliki needs to lead all Iraqis, not just Shiites.
He told the Iraqi leader in a telephone call that he must govern in an "inclusive manner, promote stability and unity among Iraq's population, and address the legitimate needs of Iraq's diverse communities," a White House statement said.
The top US military officer, General Martin Dempsey, too blamed the Iraqi government for the deepening sectarian mire.
"There is very little that could have been done to overcome the degree to which the government of Iraq had failed its people," the chairman of the Joint Chiefs of Staff said.
Former US commander in Iraq David Petraeus also rounded on the premier.
Petraeus, lauded for reviving America's fortunes during the worst period of a costly eight-year war, warned at a conference in London that Washington risked becoming an "air force for Shiite militias" and supporting "one side of what could be a sectarian civil war" if political reconciliation was not agreed.
Washington has deployed an aircraft carrier to the Gulf and sent military personnel to bolster security at its Baghdad embassy, but Obama insists a return to combat in Iraq is not in the cards.
The United States spent billions of dollars over several years training and arming Iraqi security forces after disbanding the Sunni-led army following the 2003 invasion that ousted dictator Saddam Hussein.
But the security forces wilted when faced with the militant offensive on June 9 which saw insurgents quickly capture Mosul, a city of some two million people, and then parts of Salaheddin, Kirkuk and Diyala provinces.
Some abandoned their vehicles and uniforms when faced with the insurgents.
The Sunni fighters have been led by the powerful Islamic State of Iraq and the Levant, but also include a wide coalition of other Sunni Arab militant groups, as well as loyalists of executed dictator Saddam Hussein.
Though the alliance has made significant territorial gains, the wildly divergent ideologies of its constituent groups means it may fracture over time, analysts say.
And while they struggled in the early part of the offensive, Iraq's security forces appear to be performing better in recent days, managing to make advances in certain areas, though militants have made their own gains elsewhere.
- 'Stiffening their resistance' -
The Pentagon has noted that Iraqi forces were "stiffening their resistance" around Baghdad, while the increasingly open assistance from Shiite militia groups towards government soldiers and policemen has also played a major role.
With regional tensions rising, Iranian President Hassan Rouhani said the Islamic republic "will do everything" to protect Shiite shrines in Iraqi cities against the militant assault.
And Saudi Arabia warned of the risks of a civil war in Iraq with unpredictable consequences for the region, while the United Arab Emirates recalled its envoy to Baghdad, voicing concern over "exclusionary and sectarian policies".
An assault on the Baiji oil refinery in Salaheddin province, north of Baghdad on Wednesday further spooked international oil markets, though officials and analysts said the country's vast oil exports were safe -- for now.
Officials and employees said security forces controlled the refinery, but that fighting was continuing sporadically on Thursday, with insurgents still inside the complex itself.
World oil producers have cautiously watched the unfolding chaos in Iraq, which exports around 2.5 million barrels of oil per day, and said that the country's vast crude supplies, mostly in the south, were safe for now.