New Orleans held a parade for Martin Luther King Day

On Monday, Mr Nagin had said God must be "mad at America... for being in Iraq under false pretences".

However, outrage forced a retraction, and he described some of his remarks as "totally inappropriate".

He also said he had not meant to offend anyone with his call for New Orleans to be a "chocolate" - or black - city.

Mr Nagin, who is black, said he had merely meant to convey that blacks were a key part of New Orleans' history and culture, and should be encouraged to return.

'Everybody welcome'

On Monday, Mr Nagin told an audience on Martin Luther King Day that God was angry at the US for the Iraq war.

"Surely God is mad at America. He sent us hurricane after hurricane after hurricane, and it's destroyed and put stress on this country," Mr Nagin said.

"Surely he doesn't approve of us being in Iraq under false pretences.

"But surely he is upset at black America also. We're not taking care of ourselves."

He also said that New Orleans must be a mostly black city again because "it's the way God wants it to be".

"This city will be chocolate at the end of the day," he said.

On Tuesday, Mr Nagin said his comments about God were inappropriate and he needed "to be more sensitive and more aware" of what he was saying.

"I want everybody to be welcome in New Orleans - black, white, Hispanic, Asian - because that's the kind of city that we deserve going forward," he said.

Mr Nagin added that he had also hoped to make the point that when blacks did return, they should work to stamp out the crime and political wrangling that had held them back.

New Orleans was about two-thirds black before Hurricane Katrina drove many residents to flee last year, and some fear that planned reconstruction will not encourage poor residents to return home.

'Jaws dropping'

The mayor has made a number of outspoken comments since last August's hurricane. He is seeking re-election in polls scheduled for April.

A New Orleans city councillor said earlier that "everybody's jaws are dropping" at his remarks on Monday.

"Who really cares what the racial make-up of the city is as long as it works for everybody?" Oliver Thomas asked rhetorically.

Only a fifth of the city's population of half a million has returned since the mass evacuations in the wake of the 29 August hurricane and subsequent flooding.

Most people are living in areas that did not suffer flood damage and where services have been restored, yet vast swathes of the city hit by deep flooding are still without power.