At least two people have been killed as the strongest Atlantic Ocean hurricane ever measured crashed into Caribbean islands.
The most powerful Atlantic hurricane on record is heading to Puerto Rico, the Dominican Republic, Haiti and Cuba and could also slam into the US state of Florida.
French President Emmanuel Macron said that the impact would be "harsh and cruel".
He announced a national reconstruction plan after chairing a crisis meeting in the French capital, Paris.
The hurricane has caused significant damage in the Caribbean, causing floods and destroying homes throughout the region.
The French overseas territories minister Annick Girardin said on Wednesday that Hurricane Irma had left at least two people dead in the islands of Saint Barthelemy and Saint Martin.
People make Hurricane Irma preparations at a Winn Dixie store in Hallandale, South Florida, September 6, 2017. /AFP Photo
People make Hurricane Irma preparations at a Winn Dixie store in Hallandale, South Florida, September 6, 2017. /AFP Photo
He said two people were dead and two others were seriously injured as the hurricane had destroyed homes and flooded streets.
The situation can change anytime, Girardin told journalists before leaving for the areas hit by the category-five storm.
It brought gusting winds of up to 294 kilometers per hour, according to weather experts.
The hurricane slammed into in Barbuda, part of the twin island nation of Antigua and Barbuda, just before 06:00 GMT.
People flocked to markets for food as thousands of residents have been evacuated from at-risk areas. Airports have been closed on several islands that are popular holiday destinations.
Saint Martin, "Sint Maarten" in Dutch, is located south of the island of Anguilla and is divided between France and the Netherlands. Saint Barthelemy lies to the southeast of Saint Martin. It is a French holiday destination popularly known as St Barts, administered with the status of a French collectivity.
(With input from agencies)