Bush's visit comes as Gustav's death toll jumped to 16 in the US. Many victims died in traffic accidents, and two in a post-storm tornado.
Gustav made US landfall on Monday as a Category 2 storm [GALLO / GETTY]
Some of the Gulf Coast's nearly almost two million evacuees began heading home on Wednesday, despite warnings by Ray Nagin, the New Orleans mayor, that the city was still in a "very, very, vulnerable state".
But with neighbouring towns already welcoming residents back, Nagin had little choice but to let residents return.
"I don't want people heading in yet,'' Nagin said.
"But if they jumped the gun, we will let them through.''
Evacuees returned to find that nearly 800,000 homes in Louisiana were still without power, including about 77,000 in New Orleans.
Hospitals were running on generators, and some had to move patients who they feared would suffer without air conditioning.
The storm killed at least 94 people as it wreaked havoc across the Caribbean.
What was left of Gustav moved north into the US state of Arkansas, knocking out power to nearly 100,000 homes and businesses there.
Lashing winds and several centimetres of rain caused flash flooding in parts of the state.
Several schools were closed as water inundated saturated ground and flooded onto roads.
As refugees from Gustav returned home, two more tropical storms, Hanna and Ike, led forecasters to predict they could reach US shores later in the week.