Former US President Bill Clinton has said Americans have been "profoundly disturbed" by the death and dislocation caused by Hurricane Katrina.
Clinton said authorities misunderstood the poor
In a BBC interview, Mr Clinton said Americans were troubled by the inadequacy of Washington's response.
He said the unequal suffering of poor and black people is likely to make the US more sensitive to social divisions.
Mr Clinton also said his efforts to tackle global poverty and Aids had been harmed by US and UK policy on Iraq.
"Americans were profoundly disturbed by the losses suffered and by the sense that maybe our government did not perform as well as it should have," Mr Clinton told the BBC Radio 4's Today programme.
"There was a profound sense of grief at the magnitude of the losses and not only the death but the dislocation of a million people. "And I think people were very sensitive to the fact that it disproportionately affected Americans of colour, principally African Americans, and low income Americans.
President George W Bush appointed Mr Clinton and his father, former President George Bush Snr, as special envoys in the hurricane affected areas.
Mr Clinton said the thing that "pained me most" was that those taking the decisions did not appear to understand how poor people lived.
"I don't believe there was deliberate racism in the response to this at all," he said.
He said adequate systems were not in place in the hurricane-hit region to help the needy get out of the New Orleans and surrounding areas.
Aids and poverty
Mr Clinton was in New York hosting the Clinton Global Initiative conference, on the sidelines of the UN summit, to raise funds to help tackle global poverty and Aids.
Organisers of the three-day conference, which brings together more than 800 participants from the public and private sectors, say they expect financial pledges to exceed $500m (£276m).
But the former president said aid work including his own was being hampered by the actions of the US and UK in Iraq.
"For the US and the UK it leaves us less money to spend on other things, and less political capital because the position taken by the American and British governments is basically the minority position in the world," he said.
But he said he wanted to make delegates aware that they should take responsibility to tackle world problems, even if they disagreed with their governments on certain issues.
He said his Aids project was operating at a fraction of the cost of schemes run by most governments or international agencies, because it was able to set up new systems and put them in place quickly.