Florence continues to dump rain on North Carolina as numerous neighbourhoods battle flood waters which have submerged some parts.
Emergency management authorities in storm-weary North Carolina said Monday that 25 people had died since Hurricane Florence, now a tropical depression, struck the US East Coast, bringing the death toll to 31.
At least six more deaths have been recorded in neighbouring South Carolina, as rain-bloated waterways threatened more flooding with the potential for dam failures and landslides.
A tornado watch was issued for parts of North and South Carolina as emergency management officials also warned of the potential for dam failures and landslides.
"This is an epic storm that is still continuing," North Carolina Governor Roy Cooper said at a press conference.
This is a monumental disaster for our state."
Cooper said there have been 17 confirmed storm-related deaths in North Carolina from Florence, which made landfall on the state's Atlantic coast on Friday as a Category 1 hurricane. "We hope there are not more," Cooper said.
More than a dozen rivers across North Carolina were at major flood stage on Monday or threatening to rise to critical levels.
"River flooding is dynamic and it's happening all over our state," Cooper said.
"Many roads in our state are still at risk of floods," he said, warning people who have been evacuated not to return home yet and not to go out if they do not need to. "Please don't make yourself someone who needs to be rescued," he said.
Wilmington, on the banks of the Cape Fear River in North Carolina, was almost completely cut off by land but emergency management teams managed to truck food and water overnight into the port city of 120,000 people.
North Carolina emergency response department officials said that 23 truckloads of Meals, Ready to Eat -- packaged US military rations -- and crates of bottled water had been sent into Wilmington.
"We're dealing with some very, very tough situations with respect to the impassable roads coming into the city of Wilmington," Mayor Bill Saffo told residents on Twitter. "As the water recedes things will get better.
"We're going to be OK," Saffo said. "We're going to get through this."
Flash flood warning
In Fayetteville, the Cape Fear River was expected to reach major flood stage at 17.6 metres on Monday and hit nearly 18.9 metres on Tuesday before receding.
The Deep River at Ramseur was slightly above major flood stage at 7.8 metres.
"It's worrying to watch the water slowly rising," said Denise Harper, a resident of Grifton, another small North Carolina town threatened by rising water in a nearby creek and the Neuse River.
"A lot of people have evacuated already," Harper said.
More than half a million people in the Carolinas remained without electricity on Monday, according to emergency officials.
The National Hurricane Center (NHC) warned that Florence, which has been downgraded to a tropical depression, continues to dump heavy rain on parts of North Carolina and northeastern South Carolina.
"Flash flooding will continue over portions of the western mid-Atlantic regions," the NHC said.
The National Weather Service said there is an "elevated risk for landslides" in North Carolina.
North Carolina officials said there has been a small dam breach that did not cause any significant damage and they were monitoring other structures closely.
Numerous roads across eastern North Carolina were blocked by fallen trees and flooding including parts of I-95, a major north-south artery.
Secretary of Homeland Security Kirstjen Nielsen announced meanwhile that she plans to visit North Carolina on Monday to discuss the response and recovery efforts and tour flood-affected areas.
President Donald Trump has also announced plans to visit the flood-hit region this week but a date has not yet been set.
"We're going to need significant resources to recover," Cooper, the North Carolina governor, said.