The death toll from Hurricane Katrina in the United States has climbed to 1,037, after Louisiana officials raised the number of confirmed fatalities in that state to 799.

There were 219 dead in Mississippi and 19 deaths confirmed in Florida, Alabama, Georgia and Tennessee from the August 29 storm.

Louisiana, the state hardest hit by the hurricane, which caused flooding in New Orleans, raised its death toll from the 736 it had reported as of Monday evening.

Mississippi officials did not return calls for comment on the latest numbers in that state, which last updated its death toll late last week.

Recovery teams in New Orleans have now begun moving from house-to-house to search roof cavities.

As the city braces for more possible evacuations, Mayor Ray Nagin says he hopes former residents will eventually come to terms with their loss.

"To try and get as many people as possible to come into the city of New Orleans to at least take a peek, and see what they have left, and what they have lost - so that they can get closure," he said.

A British woman is the only foreign national known to be among the people killed by Hurricane Katrina, the US State Department says.

The State Department did not release the British victim's name or where she died, but says the woman was a long-time US resident.