(CNN) - President Barack Obama said Sunday that the impact of Hurricane Irene "will be felt for some time." Affected East Coast residents still are at risk of power outages and flooding, he said.
He thanked emergency responders for their efforts.
"We continue to have search and rescue personnel on alert," the president said.
Homeland Security Secretary Janet Napolitano pledged that the federal government will assist states responding to or recovering from Hurricane Irene.
"I urge all Americans to take prudent steps to stay safe," she said at the White House press conference.