New Orleans Mayor Ray Nagin criticized the cleanliness of Philadelphia after a visit to the city last week. On Sunday, he apologized for his remarks.

"Let me tell you something. You ought to go to Philly and you will appreciate how clean New Orleans is," Nagin said Saturday to a crowd of New Orleans residents concerned about the city's recovery from Hurricane Katrina.

"Just go and walk around Philly a little bit and you will appreciate," Nagin said. " ... We still have some work to do but we definitely beat them by a long shot."

Nagin struck a different tone when he was in Philadelphia on Thursday, thanking the city for providing shelter to displaced New Orleans residents after the storm.

The mayor and officials of his administration came to Philadelphia to learn about the city's efforts to demolish blighted buildings and replace them with new developments.

"That was a big learning piece for us today," he said then.

On Sunday night, WPVI-TV in Philadelphia reported that a spokesman for Philadelphia Mayor John Street said Nagin apologized.

Nagin told the television station that he was trying to focus on the positive in New Orleans and its rebuilding efforts.

"I intended no disrespect to the City of Philadelphia," Nagin said. "We are truly thankful for the generosity of our hosts and look forward to a long, positive working relationship between our cities."