Helene is "an unprecedented storm" for western North Carolina, requiring an "unprecedented response," North Carolina Gov. Roy Cooper said Monday.

"We’re dealing with a situation that is unlike anybody’s ever seen in western North Carolina," he said.

The damage is "extensive and devastating" and is "going to require significant resources, both in the short-term and the long-term," the governor said.

Ninety-two rescue teams are out conducting search and rescues right now, Cooper said.

More than 300 roads are closed and some bridges have been destroyed, officials said.

Over 7,000 North Carolina residents have registered for FEMA individual assistance and that money is already flowing in, according to Will Ray, director of North Carolina Emergency Management.

FEMA Administrator Deanne Criswell promised that the agency will "be here as long as it takes to finish this response and continue through the recovery."

"We have the resources here in North Carolina to help," Criswell said. "We will continue to send additional resources in."

Homeland security adviser Liz Sherwood Randall said the full extent of the damage from the hurricane is still unclear.

“It probably will take several more days, as communities begin to be opened up by the debris clearance on the roads, and we can get in, and really understand what's happened to them," she said.

Sherwood-Randall said about 600 people are unaccounted for.

“We're very hopeful that some of those people just don't have cellphones working and actually are alive," she said.

Sherwood-Randall said 3,500 federal response personnel have been deployed to the region and additional personnel is expected to arrive in the coming days.

With communication remaining a major challenge, Sherwood-Randall said, "Today, FEMA will install 30 Starlink receivers in western North Carolina to provide immediate connectivity for those in greatest need."

She also highlighted that in states that have received major disaster declarations, FEMA is working to distribute serious needs assistance, which gives "an immediate $750 direct payment to eligible households, to allow them to pay for essential items like food, baby formula, water, medications and other emergency supplies."

-ABC News’ Molly Nagle

Sen. Rick Scott, R-Fla., is calling upon the Senate to reconvene to approve an emergency aid package for victims of Hurricane Helene.

"While I know from my experience with previous hurricanes that FEMA and [Small Business Administration] damage assessments take time, I am today urging Majority Leader Chuck Schumer to immediately reconvene the U.S. Senate when those assessments are completed so that we can pass the clean supplemental disaster funding bill and other disaster relief legislation, like my Federal Disaster Tax Relief Act, needed to ensure the full recovery of families in all impacted communities," Scott said in a statement Monday.

Any additional funding, beyond the funding approved by President Joe Biden and able to be drawn down from FEMA, would need to be approved by both chambers of Congress.

The Senate let out on Wednesday after approving a stopgap funding bill to keep the government funded through Dec. 20. The Senate is not scheduled to return until Nov. 12. The House is also out of session and would need to return to approve any aid.

-ABC News’ Allison Pecorin

Click here for a list of charities and organizations that are supporting relief efforts, including the Red Cross and Americares.