President Joe Biden arrived in New Orleans on Friday at the start of a visit to the US state of Louisiana to survey the damage caused to the region by Ida, the storm that left more than one million homes without power and killed at least 55 people.
“We’re in this together,” Mr Biden said in LaPlace, Louisiana, to the west of New Orleans.
“I promise we’re going to have your backs.”
The US president walked the streets of a hard hit neighbourhood and told local residents, “I know you’re hurting, I know you’re hurting.”
Ida was classified as a Category 4 hurricane when it smashed into the southern state on Sunday, but has since weakened to a post tropical depression that has unleashed record-setting rainfall along much of the East Coast.
Much of Louisiana lay under vast expanses of brown water on Friday but the state has seen some small signs of progress, with power returned to a sliver of New Orleans and crews clearing fallen trees and debris from roads.
Mr Biden pledged robust federal assistance to get people back on their feet and said the government had already distributed $100 million directly to state residents in the form of $500 cheques. Many people, he said, don’t know what help is available because they don't currently have mobile phone service.
Hundreds of thousands of homes and businesses are still without power, but utility officials said most of the city should have power back sometime next week.
Mr Biden sympathised with those who are still without power and said the federal government will supply generators to provide electricity.
“I know you've got to be frustrated about the restoration of power,” Mr Biden said, and added the government was working “24/7" with electric companies. Officials have also been working to provide food and water, he said.
At least nine deaths were reported in Louisiana, but Ida caused far more fatalities in the north.
Mr Biden's visit comes days after the storm's remnants struck the US north-east and mid-Atlantic regions, which suffered “historic” flooding and devastating tornadoes.
“This storm has been incredible, not only here but all over the East Coast,” Mr Biden said during a meeting with officials in Louisiana.
New York City Mayor Bill de Blasio said weather projections had failed to predict such a cataclysmic downpour.
“We’re getting from the very best experts projections that then are made a mockery of in a matter of minutes,” he said. “That turned into the biggest single hour of rainfall in New York City history with almost no warning.”
Catastrophic flooding has left at least 46 dead in five north-eastern and mid-Atlantic states, Reuters reported on Friday.
By midday Friday, the region was still trying to return to normal following the storm.
Ida’s hit on the north-east and mid-Atlantic is likely to have pushed the storm’s overall economic losses and damages into the $50-$60 billion range, disaster modeller Chuck Watson said.
Several US states have declared states of emergency.
In a televised address on Thursday, Mr Biden pledged robust help for the north-east and Gulf Coast regions, saying extreme events like Ida are a reminder that the climate crisis is real.
“These extreme storms, and the climate crisis, are here,” Mr Biden said. “We must be better prepared. We need to act.”
The president added he would order the use of military drones and satellites to speed up the “complicated and really dangerous” repair work.
He also ordered the use of America’s critical petroleum reserve in case of the disruption of oil supplies, with the Energy Department announcing on Thursday that it will release 1.5 million barrels of petroleum from the nation's emergency stockpile.
At least 15 people have died in New York City, including 11 who were trapped in basements, the New York City Police Department said.
Floodwaters and a falling tree also took lives in Maryland, Pennsylvania and Connecticut. Four died in Pennsylvania and a state trooper death was reported in Connecticut.
Another person died in Maryland.
At least 25 others were killed in New Jersey, The Associated Press reported.