Donald Trump said on Thursday that restoring electricity was a priority as he arrived in storm-ravaged Florida, where eight retirees died after Hurricane Irma knocked out power to their nursing home.
The US President touched down in Fort Myers with his wife, Melania, on Thursday afternoon, as they prepared to meet storm victims.
Observers noted that the First Lady - who was ridiculed for wearing high heels for the journey to Texas in the wake of Storm Harvey - changed outfits en route from the White House in Washington.
Touching down in Florida, she had swapped ballet pumps for trainers, changed cream trousers for white trousers and tucked her hair under a white baseball cap similar to one worn by her husband.
Meanwhile, a hurricane formed off the southwestern coast of Mexico, triggering warnings of life-threatening storm conditions for a long stretch of coastal communities including the resort city of Acapulco, forecasters said.
In Florida, more than four million people were still without electricity on Thursday, four days after Irma made landfall in the Florida Keys as a powerful Category Four storm.
Trump, speaking at the White House before flying to Florida, said the federal and state authorities were "doing a great job on power."
"There's never been anything like this," he said. "We have the largest assemblage of human beings ever in one area for power, and rapidly it's being turned on."
Florida Governor Rick Scott said earlier this week that 30,000 utility workers from out of state were helping with the effort to restore electricity in the state.
Meanwhile, authorities have launched a criminal investigation into the eight deaths at a nursing home in Hollywood, north of Miami, which had been without air conditioning since Irma struck.
Governor Scott said he was "absolutely heartbroken" to learn of the "unfathomable" deaths at the facility and promised to "aggressively demand answers."
Three of those who died were in their nineties, including 99-year-old Albertina Vega. The youngest was 70, according to the Broward County Medical Examiner's office.
The deaths brought the total number of storm-related fatalities in Florida to 20 and illustrated the urgency of restoring power.
Trump and his wife, Melania, will be briefed on hurricane recovery efforts in Fort Myers and then head to nearby Naples to meet storm victims, the White House said.
As Trump visited Florida, French President Emmanuel Macron wrapped up a visit to the French overseas territories of Saint Martin and Saint Barts, two Caribbean resort islands which were devastated by Hurricane Irma.
The storm left around 40 people dead in the Caribbean before churning east and pounding Florida.
Macron pledged Wednesday on Saint Barts, population 9,000, that an emergency relief fund for victims would be operational by Monday.
France, Britain and the Netherlands have been criticized for the pace of relief efforts for their overseas territories ravaged by the storm.
Islanders have complained of a breakdown in law and order and widespread shortages of food, water and electricity.
Touring Saint Martin, Macron was at times jeered by people waiting for aid supplies or hoping to catch flights to France to escape the devastation across the island.
British Foreign Secretary Boris Johnson visited the British Virgin Islands and Anguilla on Wednesday and pledged "absolute commitment" to Britons there.
Foreign Secretary responds to UK criticism
The Miami-based National Hurricane Center said meanwhile that Hurricane Max was swirling in the eastern Pacific about 40 miles (65 kilometers) southwest of Acapulco and expected to make landfall Thursday afternoon.
As of 10:00 am (1500 GMT), the Category One storm had top winds of 80 miles (130 kilometers) per hour and was moving east at seven miles (11 kilometers) per hour, the NHC said.
Authorities declared a hurricane warning for 300 miles (485 kilometers) of Mexico's coast stretching from Zihuatanejo to Punta Maldonado.
"Preparations to protect life and property should be rushed to completion," the hurricane center warned.
Max was expected to bring dangerous storm surge that will likely cause "significant" coastal flooding, accompanied by "large and destructive waves."