Florida Senator Bill Nelson has said his state "desperately needs gasoline" as thousands of residents try to evacuate the path of Hurricane Irma.

The storm, classified as a Category 5, has already devastated parts of the Caribbean and left a million people without power in Puerto Rico.

The storm was increasingly likely to rip into heavily populated South Florida early on Sunday, prompting the Governor Rick Scott to declare an emergency and officials to impose mandatory evacuation orders for parts of the Miami metro area and the Florida Keys. Forecasters said it could punish the entire Atlantic coast of Florida and rage on into Georgia and South Carolina. The Keys and parts of South Florida were placed under a hurricane watch on Thursday.

Upwards of 26 per cent of gas stations in the Miami-Fort Lauderdale and West Palm Beach-Fort Pierce areas are completely empty according to GasBuddy, which tracks petrol prices and availability.

Though, part of the problem is the massive evacuation taking place the other is that Hurricane Harvey just inundated Texas refineries that supplied Florida.

Mr Nelson said on CNN that he sent a slew of emails to his Senate colleague Marco Rubio, the Federal Emergency Management Agency (FEMA), the National Oceanic and Atmospheric Agency (NOAA), and other the Federal Trade Commission (FTC).

He was worried about FEMA running out of money after the massive response required after Hurricane Harvey and has asked that there be flexibility in the aid package for Texas so that some of the funds can be allocated to minimising the destruction of Irma.

He has asked NOAA for more storm tracking information and planes that can monitor the hurricane's impact once it does make landfall.

Mr Nelson also warned the FTC of possible price gouging as petrol stations that are operational may seek to take advantage of people's desperation.

Barbuda, Hurricane Irma – in pictures Show all 7 1 /7 Barbuda, Hurricane Irma – in pictures Barbuda, Hurricane Irma – in pictures A roof-less house in Barbuda ABS TV Barbuda, Hurricane Irma – in pictures A mobile network tower snapped in two by the hurricane ABS TV Barbuda, Hurricane Irma – in pictures The hurricane left debris strewn across the island Barbuda, Hurricane Irma – in pictures Rubble in the aftermath of the hurricane ABS TV Barbuda, Hurricane Irma – in pictures The destruction in Barbuda, as seen from an ABS TV helicopter ABS TV Barbuda, Hurricane Irma – in pictures As well as destroying most houses, the hurricane also left plenty of flooding ABS TV Barbuda, Hurricane Irma – in pictures Barbudan residents survey the damage ABS TV

According to the Wall Street Journal, Florida normally keeps a seven day supply of petrol on hand "and shipments are still coming in: Tankers are unloading at ports like Tampa, and barges are travelling along the Gulf Intracoastal Waterway."

However, trucks are experiencing long delays at fuel racks and preventing them from delivering to gas stations around the state.

The fear of what is predicted to be one of the most powerful storms in US history has caused a state-wide panic to buy gasoline because the path of the storm, though expected to be on the east coast, could change.

"Regardless of which coast you live on be prepared to evacuate," Governor Scott said.

All road tolls have been suspended in the state and airlines are offering deep discounts for those looking to leave the area in order to minimise the potential loss of life in what the governor called a "storm you cannot just sit and wait through".

Mr Scott has said that he spoke to FEMA, the White House, and the Environment Protection Agency about also loosening federal rules and regulations on gasoline distribution restrictions that may hinder getting fuel to stations.

He also asked that people only take the fuel they need as well in order to provide enough for everyone in the evacuation zone.

The state is also providing bus transportation for those with special needs to evacuate.