Iraqi prime minister Nouri al-Maliki is calling on residents of Fallujah to drive out Islamist militants linked to al-Qaeda, who took over the city last week.
Iraqi forces are preparing to recapture the city, and Mr Maliki said that if the people expelled "terrorists", it would ensure "their areas are not subjected to the danger of armed clashes".
Much of the city is reported to be controlled by the Islamic State in Iraq and the Levant, known as ISIS, the BBC reports.
The US is speeding up the delivery of military equipment to the government and was looking to provide an additional shipment of Hellfire missiles as early as this spring, White House spokesman Jay Carney said.
He said Washington would also provide more surveillance drones - 10 in the next few weeks and another 48 later in the year.
Mr Carney said it was up to the Iraqis to take the lead but the US was "working closely with the Iraqis to develop a holistic strategy to isolate the al-Qaeda-affiliated groups".