Iraq's interim government has said it will send food and medical teams into the city of Falluja.
US marines are bombing Falluja insurgents from the air
The move follows an appeal by the Red Cross, which said it feared for the plight of civilians after the US-led assault against insurgents.
US-led forces continue to encounter fierce displays of resistance in southern zones of Falluja.
But a top US commander says the offensive there has "broken the back of the insurgency" across Iraq.
Lt Gen John Sattler said the operation had "taken away this safe haven" which he alleged was used as a base for the nationwide Iraqi rebellion.
A government spokesman said health services in Falluja would be restored, and housing and reconstruction needs assessed.
He added that residents who had fled would be helped to return, and each family would receive $100 compensation.
Until now, Iraqi and US authorities, back in charge of much of the city, had played down warnings of a humanitarian crisis.
The International Committee of the Red Cross (ICRC) had said that the city was without running water or electricity, and that the wounded were still unable to reach medical care because of the fighting.
It called for an independent assessment of the situation facing those still living in the city.
"The first concern we have is over the safety of the people in Falluja," spokesman Ahmed Rawi said.
He said the ICRC was negotiating with US forces to open a "humanitarian corridor" into the city.
In other developments:
In western Baghdad, a car bomb explodes outside a police station, killing two people and injuring at least four
- Car bombs in the oil refining city of Baiji and outside Samarra kill eight civilians, reports say
- Two Iraqis are killed by an explosion in the rush hour near a recruitment centre in the northern city of Kirkuk
- Rebels fire mortars at government offices and kill the governor's bodyguard in Mosul, where US troops are trying to put down an uprising by insurgents
- A mutilated woman's body found in Falluja on Sunday has been flown out of Iraq for DNA tests to see if it is that of kidnapped aid worker Margaret Hassan.
The BBC's Jennifer Glasse, with US marines in Falluja, says tough battles are still being fought in the city's southern neighbourhoods.
"We're playing surrender messages trying to encourage the remaining pockets to come out and end hostilities but it's been relatively unsuccessful," said the commander of the unit she is with.
Marines are calling in aerial bombing raids to hit houses where insurgents are taking shelter.
The total US death toll in the offensive, which began on 7 November, stands at 51. About 425 American troops were wounded in action. Eight Iraqi soldiers have died.
Lt Gen Sattler said reports of 1,200 fighters killed was "probably a safe number". The number of civilians killed is unknown.
Lt Gen's assessment of the impact of the Falluja offensive was more optimistic than that of marine intelligence officials, AP news agency reported.
They cautioned the insurgency would rebuild if the US military did not maintain a large presence in Falluja.
Meanwhile supporters of the Iraqi radical cleric, Moqtada Al-Sadr, say one of his aides has been arrested by police in the city of Najaf, Reuters reported.
They say Sheikh Hashem Abu Raghif is being punished for speaking out against the US-led assault on Falluja.