The city of Wilmington, North Carolina, has been entirely cut off by floodwaters from Tropical Depression Florence, forcing North Carolina officials to call for additional help from state law enforcement and the National Guard.

Roads leading in and out of the city were under water Sunday night, forcing residents to wait for hours outside the few stores that were open for basic necessities. Police were allowing only 10 people at a time inside the door of one store.

During a news conference Sunday, Woody White, chairman of the board of commissioners of New Hanover County, said additional rainfall Saturday night made roads into the city impassable.

(MORE: Florence Death Toll Continues to Rise in North Carolina )

"Our roads are flooded," he said. "There is no access to Wilmington."

He said water and food would be flown into the city that is home to about 120,000 people.