North Carolina may bear the worst of the storm, as current forecasts show Maria brushing its coast Wednesday morning.
Although it's not currently predicted to make landfall along the coast, Maria is the third hurricane to affect the US in the last month.
"It is likely that some direct impacts will occur along portions of the coast by midweek," the National Hurricane Center said in an advisory Sunday.
Some of the US coast may be under a tropical storm or hurricane watch later Sunday, the center said. Those on the Carolina and mid-Atlantic coasts are warned to monitor the storm's progress.
"Regardless of the exact forecast track," the storm is so big that "tropical storm-force winds could reach a portion of the North Carolina coast by mid-week," the NHC said.
Hurricane-force winds extend outward up to 60 miles from the center of the storm, the NHC said, and tropical-storm-force winds extend outward up to 230 miles.
Maria's sustained winds weakened Sunday to 90 mph from 105 mph earlier in the day, the NHC said. The center said it expected the storm to weaken further by Monday night or Tuesday but would remain a storm packing a powerful punch.
"Swells generated by Maria are increasing along portions of the southeastern United States coast and Bermuda and will be increasing along the Mid-Atlantic coast later today," the center said Sunday, warning that such swells can cause "life-threatening surf and rip currents."
The storm was about 625 kilometers (about 390 miles) south-southeast of Cape Hatteras, North Carolina, moving north at about 8 miles per hour, the NHC said in its 11 p.m. advisory.
The five-day tracking model
shows Maria maintaining hurricane strength through Friday as it makes it way north before turning northeast
and heading further out into the Atlantic.
Millions of people in the Caribbean are still reeling
from Hurricane Maria's devastation. At least 10 people were killed in Puerto Rico, where much of the US territory is without power and many are without water.
That's after the storm destroyed the island of Dominica
, killing at least 15 people there. It also hammered the Dominican Republic, the US Virgin Islands and the Turks and Caicos, a British overseas territory.