Nagin said his city also welcomed outside investors in a $1 billion expansion of its port, the eighth-largest in the United States, but had not talked to any Chinese port operators that might be interested in the project.

The US government restricts foreign investment in key ports for security concerns. It forced Dubai's DP World to give up control of six US port terminals it acquired with its 2006 purchase of British port operator P&O.

"The future is going to play itself out," said Nagin, who was in Shanghai to tour a major port on the outskirts of the city. "I think over time you are probably going to see some loosening up of the restrictions."

Other Chinese companies have also visited New Orleans seeking opportunities in the property, tourism and logistics sectors, said Erin Butler-Mueller, commercial officer with the New Orleans US Export Assistance Centre, although she did not name any companies.

Nagin, in his second term as mayor of New Orleans, said the city had spent $6 billion to $7 billion rebuilding after the devastation of Hurricane Katrina in August 2005.

The city has secured half of the $10 billion in additional financing it needs for full restoration, he added.

Katrina flooded more than 80 percent of the city and forced its near total evacuation.

New Orleans officials said in March that they would challenge a US Census Bureau estimate that put the city's population at 239,000, just over half the number before Katrina struck.

Nagin said other counts have found as many as 318,000 residents in the still-recovering city. "We will file our appeal, probably in the next 30 to 60 days," he said. "And we think that we are going to be able to prove our case."

The mayor has said that a lower number would shrink federal aid, discourage Katrina refugees from returning and harm efforts to rebuild the tourism industry.