She added: "We will stand with these communities for as long as it takes and make sure they are able to rebuild."
A North Carolina county that includes the mountain city of Asheville reported earlier Sunday that 30 people were killed due to the storm, pushing the overall death toll to at least 84 people across several states.
Biden on Sunday evening made calls to several state and local government officials in areas impacted by the hurricane, including Georgia Gov. Brian Kemp; North Carolina Gov. Roy Cooper; Valdosta, Georgia Mayor Scott Matheson; and Taylor County, Florida Emergency Management Director John Louk.
Biden told the officials the administration "will continue providing support to impacted communities -- for as long as it takes," according to the White House.
Biden, who spent much of the weekend at his beach house in Delaware, has received frequent updates on the storm from FEMA administrator Deanne Criswell, homeland security adviser Liz Sherwood-Randall and other officials. Harris received similar briefings while on board Air Force Two, according to the White House.
The White House said Biden directed Criswell to figure out what can be done to accelerate support to isolated communities that are having difficulty accessing assistance.
Former President Donald Trump's campaign announced earlier Sunday he'll visit Valdosta, Georgia, on Monday to survey Helene's impact on that state, one of several hotly contested battlegrounds that will be pivotal in the November presidential election.