North Carolina Governor Roy Cooper said Friday that Hurricane Florence was "wreaking havoc" on the state and threatening entire communities.
"The storm is wreaking havoc on our state," Cooper said. "We face multiple threats.
"We're deeply concerned for whole communities which could be wiped away," he said.
The governor said half-a-million people in the state were without power and the Neuse River had seen storm surge as high as 10 feet (three meters).
"Rescue workers are working in dangerous conditions that will only get worse today," Cooper said.
Hurricane Florence, which made landfall in North Carolina on Friday, will pose "significant threats" for the next 24 to 36 hours, an emergency management official said.
"This is not the end of it," said Jeff Byard, associate administrator for response and recovery at the Federal Emergency Management Agency (FEMA).
He said "24 to 36 hours remain for significant threats" from heavy rain, storm surge and flooding.
Weather forecasters said the hurricane made landfall at 7:15 am (1115 GMT) at Wrightsville Beach, North Carolina, as a Category 1 storm.
They described it as a "slow mover" which would dump copious amounts of rain on the Carolinas including as much as 40 inches (one meter) in some places.
Images of the hurricane appeared on social media sites almost immediately after the hurricane struck. Nearly two million residents chose to follow evacuation guidelines, whereas others have stayed at home.
While for the moment there have been no casualties, the authorities have still been very clear: those who have decided to stay and face the storm do so at their own risk and peril.
Luxembourgers in affected areas
Luxembourg's foreign affairs ministry has confirmed that around 75 Luxembourgish nationals live in the risk areas: in North Carolina, South Carolina, and Virginia.
That said, by Thursday evening, no Luxembourgers had contacted the Luxembourgish embassy for help.
In terms of the embassy's practical measures, the embassy in Washington has placed instructions on its website to encourage Luxembourgers to follow local evacuation guidelines and has listed emergency numbers for the embassy and consulate in New York.