US soldiers are set to be redeployed on the streets of New Orleans to fight crime for the first time since the aftermath of Hurricane Katrina.
Mayor Nagin spoke publicly alongside crime victims' relatives
The Louisiana governor asked for the National Guard to return to New Orleans after a weekend that saw six people murdered in the city.
New Orleans Mayor Ray Nagin had earlier called for 300 soldiers and some 60 state police to be sent to the city.
Crime has risen in the city after a brief drop following Hurricane Katrina.
The six deaths over the weekend raised the number of murders in New Orleans this year to 52, police said.
That figure is less than half what it was a year ago - but the city's population is also only roughly half of what it was before Hurricane Katrina forced thousands from their homes last August.
Police statistics show crime has risen in recent months.
Louisiana Governor Kathleen Blanco did not specify how many troops would be deployed in New Orleans.
Calls for soldiers to return to the streets came after six people were murdered in the city at the weekend - five of them in the same incident.
The five teenagers were found shot dead in or near a car on Saturday, in what is thought to be a drug-related attack.
Troops were last sent to the city to keep order after the hurricane
A city official, Oliver Thomas, told the mothers of the victims: "We are not going... to let hurricane crime replace Hurricane Katrina."
Mayor Nagin said New Orleans had suffered enough.
"This is our line in the sand. We're saying we're not going any further," he said.
According to the BBC's James Coomarasamy, there are concerns about external troops being allowed to police New Orleans - but city officials say safety is paramount, especially if those who fled the hurricane are to be lured back.
New Orleans has long been regarded as a hotbed of violent crime but the crime rate there fell sharply in the immediate aftermath of Hurricane Katrina.
However, residents have been complaining that a lack of adequate schooling and housing as a result of the hurricane has forced the crime rate up again.
A Florida National Guard spokesman told the Associated Press news agency some 15,000 soldiers had been sent to New Orleans in the wake of Hurricane Katrina, of which 2,000 stayed until February this year.
Some 1,500 people were killed and hundreds of thousands forced from their homes when Hurricane Katrina lashed the southern US.