In a brief video aired on ABC's Good Morning America, the president said the U.S. government has already taken immediate action, sending hundreds of emergency personnel, thousands of meals and supplies to the devastated tourist resort town where some 2,200 buildings were destroyed.

"We will be with you for as long as it takes, I promise you," he said. "Already from the darkness and the smoke and the ash, we see the light of hope and strength."

During his remarks, Biden highlighted the efforts of first responders - many of whom have been personally affected by the wildfires. Local first responders have worked around the clock searching for the missing, while volunteers deliver aid by fishing boats and local chefs prepare meals for displaced families, he noted.

Biden and first lady Jill Biden will travel to Hawaii on Monday to survey the devastation and meet with first responders, survivors and federal, state and local officials.

"I want the people of Hawaii to know that your country is with you as long as it takes," he said.

In other developments:

-- Maui County Emergency Management Agency administrator Herman Andaya defended the department's decision not to sound sirens during last week's deadly wildfire as questions intensify regarding how residents were alerted to growing threat as the deadly wildfires spread last Tuesday.

Andaya said sirens in Hawaii are used to alert people to tsunamis. Using it during the fire might have led people to evacuate toward the danger, he told reporters on Wednesday.

"The public is trained to seek higher ground in the event that the siren is sounded," Andaya said during a press conference.

"Had we sounded the siren that night, we're afraid that people would have gone mauka (to the mountainside) and if that was the case then they would have gone into the fire," Andaya said.

-- On Wednesday, officials opened the main road through town for the first time in several days, responding to frustration from residents. Officials initially closed the highway, which bypasses the charred waterfront and town center, to all but residents, first responders and employees of local businesses.

-- Hundreds of people remain unaccounted for as the death toll rose to 110. Teams, led by 20 cadaver dogs, have conducted a block-by-block search that have covered 38% of the disaster area as of Wednesday. The number of dogs would soon double to 40, Governor Josh Green said on Wednesday.

-- Identification of human remains that have been found has been slow, partly because of the intensity of the fire. Robert Dyckman, 74, and Buddy Jantoc, 79, both of Lahaina were the first two people killed in the wildfires to be identified. Maui officials have identified three others, but their names have been withheld pending family notification, Maui County said.

-- As officials work to identify the deceased, harrowing stories about those injured or killed in the wildfires have emerged from relatives and friends. Among them is Laurie Allen, who was burned over 70% of her body when the car she was escaping in was blocked by a downed tree, forcing her to flee across a burning field, her family said in a GoFundMe post.

She is burned to the bone in some places, but doctors at a burn center in Oahu hope she will regain partial use of her arms, the post said.

"The Burn Team has expressed more than once that she shouldn't be alive!" a relative wrote on the page.

-- Residents have been outraged by the tourists enjoying Maui's tropical beaches while search-and-rescue teams trawl ruins and ocean waters for victims of the deadliest U.S. wildfire in more than a century.

(Reporting by Jonathan Allen in Maui; additional reporting by Brendan O'Brien in Chicago, Julia Harte in New York, Eric Beech in Washington and Daniel Trotta in Carlsbad, California; Editing by Frank McGurty and Alistair Bell)

By Jonathan Allen