At least 50 people died in the hurricane which slammed into the northern Bahamas as a Category 5 storm while officials say they expect the number to rise significantly.
Some 2,500 people are unaccounted for in the Bahamas following Hurricane Dorian, the archipelago's National Emergency Management Agency (NEMA) said on Wednesday.
NEMA spokesman Carl Smith told reporters that some of the missing people may eventually be located.
"At this point, there are approximately 2,500 individuals registered on the Bahamian government register (of missing people)," Smith said.
"This list has not yet been checked against government records of who is staying in shelters or who have been evacuated," he said.
"Some individuals who have been evacuated from Abaco and Grand Bahama have not yet registered with social services," Smith said.
"As we are able to cross-reference our data sets we will be able to inform family members and reunite survivors with loved ones."
At least 50 people died in the hurricane, which slammed into the northern Bahamas as a Category 5 storm, and officials have said they expect the number to rise significantly.
"We're not going to speculate on what the final numbers will be," Smith said. "We understand that people are concerned and so are we."
The NEMA spokesman said more than 5,500 people have been evacuated so far from the northern Bahamas islands of Grand Bahama and Abaco, which were devastated by the storm.
He said that over the past day or so there had been a "significant reduction," however, in the numbers of people seeking to leave.
Smith also said that permission was being given to resume commercial flights to Abaco on a "limited basis," but priority would be given to relief and evacuation flights.
The NEMA spokesman said Abaco's power grid had suffered extensive damage.
"Marsh Harbour power station was completely destroyed," he said of the largest town on the island of more than 15,000 people.
An official with Bahamas Power and Light Ltd said electricity to the south of Abaco could be restored in about three weeks but it may be a few months before the rest of the island gets power.
No temporary protected status for Bahamians
The United States does not plan to invoke temporary protected immigration status for Bahamians currently in the United States, a White House official said on Wednesday.
"The Bahamians impacted by Hurricane Dorian are facing a humanitarian crisis, and the American government, international partners and private organizations continue to support them with aid and services. At this time we do not plan to invoke Temporary Protected Status for those currently in the United States," the official said.
State and federal lawmakers in Florida asked President Donald Trump to grant Bahamians Temporary Protected Status (TPS), which lets foreign nationals whose home countries have been hurt by war or natural disaster live and work in the United States.
The United States has a long history of allowing evacuees from countries such as Nicaragua, Honduras and Haiti to enter the country under the TPS program.
But Trump on Monday said the Bahamas had "tremendous problems" with allowing "very bad people" into the country and that doors could open for "very bad drug dealers" by easing immigration rules for US.-bound Bahamians.
"Everybody needs totally proper documentation," Trump told reporters.
Administration data shows the Caribbean plays a small role in the narcotics trade. Critics have accused Trump of demonising Bahamians to stop non-white immigrants from entering the United States