Mr Bush, whose approval ratings have yet to recover from the botched response to Katrina, preached optimism and pleaded for patience in the recovery effort.
"I know there's some frustration" with the flow of aid money, Mr Bush said.
"We understand people are still anxious to get in their homes. We understand people hear about help and wonder where it is. We know that," he said.
In the wake of the natural disaster, the US Congress allocated US$110 billion to the help the region get back on its feet.
To date though just US$44 billion has been spent because of political wrangling between state and local governments and federal authorities.
The president has made at least 11 visits since the storm struck and this tour will take in much of flood-ravaged coastal Mississippi and devastated New Orleans.
"I've come back on this anniversary to thank you for your courage and to let you know the federal government stands with you, still," said Mr Bush.
Eye on Ernesto
In Biloxi, Mississippi, Mr Bush said the signs of progress were obvious and praised the determination of residents to rebuild.
"Optimism is the only option," he quoted one local leader as saying. "We want to help. We want to help that optimism succeed," Mr Bush said.
His visit comes as US officials kept a close watch on Tropical Storm Ernesto as it slammed into Cuba and headed towards Florida, where Governor Jeb Bush, the president's brother, ordered a state of emergency.
Officials worried that it could regain hurricane strength before striking the southern US state, which the governor warned "may be threatened by a major disaster."
Day of remembrance
Mr Bush is expected to travel to New Orleans for a dinner with state and local officials, and on Tuesday he was to tour a city neighborhood, meeting with residents and volunteers, and make another speech.
Mr Bush has declared August 29 a national day of remembrance for Katrina, which he described Saturday as "one of the deadliest and most costly natural disasters in American history."
Images of Americans stranded on rooftops while the waters around them rose and criticism of the government poor response to the storm hammered Mr Bush's approval ratings.
It came on the back of concerns that had already surfaced about the economy and the unpopular war in Iraq.
The president was especially criticized for staying on vacation on his ranch as the storm headed towards the coast and for going ahead with a California speech on the war on terrorism.
The president insists that the federal government has learned its lesson, and overhauled its emergency management plans, and played a role in rebuilding the New Orleans levee system that failed under Katrina's onslaught.
Region prepares
Officials have tried to assure residents that there will not be a repetition of the chaos, death and despair that followed the flooding of 80 percent of New Orleans after Katrina ravaged the Gulf Coast on August 29, 2005 and killed more than 1,500 people.
The evacuation plan now includes buses, trains and planes to take people and their pets out of the danger zone. And with half the city's population still scattered across the country, there are fewer people living in the most dangerous low-lying areas.
The failed levee system has been repaired but not yet reinforced. And more than 80,000 families across Louisiana are still living in trailers that can only withstand light winds.