Iraqi officials have privately asked US President Barack Obama's administration to weigh potential air strikes targeting militants, a Western official has said.
The Obama administration is weighing several possibilities to offer military assistance to Baghdad, including drone strikes, the official told AFP on condition of anonymity.
But Baghdad has not yet formulated an official request, a US defense official said.
Faced with the Islamic State of Iraq and the Levant's spectacular assault on Mosul and seizure of a large swathe of northern and north-central Iraq, Washington is committed to "working with the Iraqi government and leaders across Iraq to support a unified approach against ISIL's continued aggression," State Department spokeswoman Jen Psaki said.
The Obama administration had long warned of the dangers posed by the militants now sweeping toward Baghdad, according to Psaki.
A US official said the Obama administration was considering sending "more weaponry" to Iraq after ISIL seized the cities of Mosul and Tikrit.
But there is no current plan to send US troops back into Iraq, where around 4,500 American soldiers died in the bitter conflict.
The US has already expedited arms shipments to Iraq this year and ramped up training of Iraqi security forces, while Congress is mulling a request for a further USD 1 billion in military aid.
In January, Washington sold 24 Apache attack helicopters to Baghdad, as well as about 300 anti-tank Hellfire missiles and two of some 36 F-16 fighter aircraft, a Pentagon spokesman said. Some of the arms have been delivered and others should be on their way in the coming months.
The new USD 1 billion includes provisions for around 200 Humvee vehicles and 24 AT-6C Texan II aircraft, but it may take months to get lawmakers' approval.
Since US forces left Iraq in late 2011, Washington has provided training assistance to Iraq's military for counterterrorism missions, including in Jordan since the start of the year.
