The hurricane has hit the US Virgin Islands with it due to reach the US mainland by the weekend. The states of Florida and Georgia are expected to suffer the most.
Hurricane Dorian was classified as Category 1 on Wednesday as Florida Governor Ron DeSantis declared a state of emergency.
"Today, I am declaring a state of emergency to ensure Florida is fully prepared for Hurricane Dorian," DeSantis said in a statement.
"It's important for Floridians on the east coast to monitor this storm closely. Every Florida resident should have seven days of supplies, including food, water and medicine, and should have a plan in case of disaster."
Georgia Governor Brian Kemp, meanwhile, held back on declaring a state of emergency urging caution while admitting "we're not sure where this storm is going."
Virgin Islands hit
Even as the storm gathered strength and hit the US Virgin Islands on Wednesday, it reportedly caused limited damage in the northern Caribbean and knocking out power on some islands.
Forecasters have said the storm could become a Category 3 hurricane as it approaches the US mainland in the coming days.
"Dorian brings uncertainty, and, for those of us who experienced the storms of 2017, uncomfortable memories," said British Virgin Islands Governor Augustus Jaspert.
Here we see an aerial view of the devastation left behind from Hurricane Irma in Tortola, British Virgin Islands in September 2017
The US part of the Virgin Islands territory consists of four larger islands and approximately 50 smaller islets and cays. The British part is made up of four larger islands, and 32 smaller ones.
Meanwhile, US President Donald Trump was keen to politicize the natural disaster by criticizing, not for the first time, the mayor of San Juan, Carmen Yulín Cruz.
Trump tweeted: "We are tracking closely tropical storm Dorian as it heads, as usual, to Puerto Rico. FEMA and all others are ready, and will do a great job. When they do, let them know it, and give them a big Thank You - Not like last time. That includes from the incompetent Mayor of San Juan!"
In response, she said the president had taken $155 million from emergency funding to spend on immigration enforcement along the US-Mexican border.
"An insult on the part of President Trump is well-received on my part," she told CNN. "That means he knows I am nothing like him."
jsi/sms (AP, AFP)