South Carolina Gov. Henry McMaster said conditions are "very dangerous" as Ian comes ashore, but so far the amount of water in places like the hospital district of Charleston is lower than expected.

"But I would ask people: Don't quit yet because this is still coming. We're not out of the woods," McMaster said.

South Carolina has positioned 90 National Guardsmen for high-water vehicle support. They have received a few requests for support, including for swift water rescue teams, said Kim Stenson, the head of South Carolina Emergency Management.

Stenson said they expect calls for damage and flooding to increase throughout the day.

A tornado threat is increasing as Hurricane Ian gets closer to the coast of the Carolinas.

Myrtle Beach and Greenville, South Carolina; Wilmington, North Carolina and Virginia Beach, Virginia, are all under tornado watch through 10 p.m.

A tornado warning is also in effect south of Wilmington.

-ABC News' Melissa Griffin

President Joe Biden pledged the U.S. would do "whatever it takes," to help Florida recover from Hurricane Ian, stressing the effort would be done as "one nation and one America," during an event at the White House marking the Jewish New Year.

"We're working very closely with the governor and the entire Florida delegation, Democrat and Republican, making sure that we can do everything we can, including now search and rescue, recovery and rebuilding efforts, but it’s going to go on for a long while. And whatever it takes, we’re going to be there, as one nation, and one America. We're not going to walk away," Biden said.

Biden noted the time of celebration is also a "very difficult time for so many Jewish families in Florida," and those with loved ones in the state.

"[O]ur heart goes out to everyone there in the state experiencing what could be maybe one of the most devastating hurricanes in the history of that state," Biden said.

-ABC News' Molly Nagle

President Joe Biden spoke with South Carolina Gov. Henry McMaster Friday ahead of Hurricane Ian's expected landfall.

Biden told McMaster the administration will provide whatever assistance South Carolina needs. Biden issued an emergency declaration for South Carolina Thursday night.

-ABC News' Molly Nagle

Caribbean islands such as Jamaica and Grand Cayman will start to experience the effects from the outer bands of Tropical Storm Ian within the next 24 hours, forecasts show. The islands will experience conditions such as heavy rain, possible flash flooding and storm surge.

The storm system will begin to rapidly intensify overnight into Monday before it closes in on western Cuba on Monday night.

As of 2 p.m., the sustained winds in the tropical storm remained at 50 mph as it moved west-northwest at 12 mph, the center about 265 miles away from Grand Cayman.

Hurricane warnings are in effect for Grand Cayman and western Cuba, while tropical storm warnings and watches are in effect in other portions of both islands.

As a hurricane, Ian is expected to peak at a Category 4 before weakening slightly as it looks to make landfall on the west coast or panhandle of Florida in the coming days.

There is still some uncertainty to the track Ian will take once the system enters the Gulf of Mexico.

The center of the storm and the worst of the impacts could end up heading toward the western coast of Florida's peninsula, including the Tampa area. The other possible scenario has the storm moving more due north and bringing a possible landfall along the Florida peninsula, impacting cities like Panama City and Tallahassee with more direct effects.

The storm will begin to impact the Florida keys and the southern portions of the state by Tuesday night.

-ABC News' Dan Peck