Obama visited New Orleans -- the city hardest hit by the disaster -- with his family at the end of a week-and-a-half vacation on the island of Martha's Vineyard in Massachusetts.
During the 2008 presidential election, Democrat Obama sharply criticized then-President George W. Bush for his administration's slow response to the flooding and devastation that played out live on television.
Ahead of November's congressional elections, Obama used his speech to highlight his administration's action since taking office, drawing an implicit contrast without naming Republicans or Bush by name.
It was a natural disaster, but also a man-made catastrophe, a shameful breakdown in government that left countless men and women and children abandoned and alone, Obama said in a speech at Xavier University.
The 2005 storm killed more than 1,800 people and caused billions of dollars of damage to the Gulf coast.
Obama noted that his director of the Federal Emergency Management Agency, Craig Fugate, had 25 years of experience in disaster management -- a marked contrast with Michael Brown, whose performance as FEMA director when Katrina hit was widely criticized and immortalized, infamously, by Bush's comment: Brownie, you're doing a heck of a job.
Democrats are expected to lose a significant number of seats and possibly majorities in both houses of Congress in November. The White House has sought to boost Democrats' chances by highlighting mistakes from the Bush years.
Obama said, I don't have to tell you that there are still too many vacant and overgrown lots. There are still too many students attending classes in trailers. There are still too many people unable to find work. And there are still too many New Orleanians ... who haven't been able to come home.
So while an incredible amount of progress has been made, on this fifth anniversary, I wanted to come here and tell the people of this city directly: my administration is going to stand with you, and fight alongside you, until the job is done, he said to applause.
Obama also touched on the most recent calamity to hit the region, the oil spill in the Gulf of Mexico, and repeated his promise to reverse the damage caused by the spill and hold energy giant BP accountable.