President Joe Biden on Thursday laid out his administration's response to Hurricane Ida, which knocked out power across the US Gulf Coast before unleashing tornadoes and devastating flooding across the north-east and mid-Atlantic regions.
"This destruction is everywhere," Mr Biden said in a televised address.
"It's a matter of life and death, and we're all in this together."
At least 25 people have been killed in Ida-related incidents, and officials warned the death toll could rise as the extent of the destruction is tallied.
Hurricane Ida hit Louisiana on Sunday as a Category 4, but has since weakened to a post tropical cyclone, the National Hurricane Centre said.
It was expected to continue steaming north and bring more heavy rainfall on Thursday across New England, where scenes of catastrophic flooding have played out across the region.
In New York City, subway services were suspended as torrents of water burst onto tracks and platforms . The surrounding area was reeling from the devastation caused by Ida, with homes and roads flooded after the storm brought up to 20 centimetres of rain stretching from Pennsylvania to Connecticut.
"We saw a horrifying storm last night, unlike anything we've seen before," New York City Mayor Bill De Blasio said on Thursday.
Mr Biden said the latest technology is being used to accelerate the restoration of power in Louisiana, noting he would order the use of military drones and satellites to assess infrastructure damage that would speed up the "complicated and really dangerous" repair work.
He also ordered use of America’s critical petroleum reserve in case of the disruption of oil supplies.
The Energy Department on Thursday announced it will release 1.5 million barrels of petroleum from the nation's emergency stockpile.
Mr Biden made a plea to private insurance companies after some firms denied their customers insurance pay outs for hotel stays because the areas they fled were not under mandatory evacuation orders.
"No one fled this killer storm because they were looking for a vacation," he said.
He also confirmed he would travel to Louisiana on Friday to meet Governor John Edwards and survey the damage caused by the storm, and was assured by the governor that his presence would not be a distraction from recovery efforts.
New York Governor Kathy Hochul declared a state of emergency on Thursday and has asked for federal help.
The devastation in the north-east comes days after Ida made landfall in Louisiana, which initially left more than a million homes with power.
Mr Biden noted that Ida was the fifth-largest hurricane to strike the US in history and had prompted the National Weather Service to issue a first-ever flood emergency for New York City and parts of Long Island.
He said extreme storms like Ida are reminder that the climate crisis is real and the nation needs to be better prepared.
"We're reminded this isn't about politics," Mr Biden said.
"Hurricane Ida didn't care if you were a Democrat or Republican, rural or urban..... This is one of the great challenges of our time."
The Atlantic hurricane season is far from over. Larry became a hurricane Thursday morning, forecast to rapidly intensify into a potentially catastrophic Category 4 storm by Sunday. The National Hurricane Centre in Miami said it’s moving west but remains far from any coast.