The US territory has asked Congress for $139bn in recovery funds. Photo: BBC News

Hurricane Maria in Puerto Rico is now one of deadliest disasters in US history. Photo: CBS News

The revised death toll is nearly 50 times the previous estimate of 64.

Governor Ricardo Rossello "accepted" the findings in a long-awaited independent investigation.

Puerto Rico has struggled to repair its infrastructure and power grid since the storm, and is asking US Congress for $139bn (£108bn) in recovery funds.

"I'm giving an order to update the official number of deaths to 2,975," Governor Ricardo Rossello said at a press conference on Tuesday.

"Although this is an estimate, it has a scientific basis."

Trump Criticised

In a statement, the White House said the federal government supported the governor's efforts to "ensure a full accountability and transparency of fatalities" in last year's hurricane.

President Donald Trump was criticised for praising the federal response to the hurricane-ravaged island in the weeks following the storm. Critics accused him of showing more concern for residents in Texas and Florida after they were hit by hurricanes.

The authorities have faced nearly a year of criticism for underreporting the true toll of Maria - the most powerful storm to hit the region in nearly 90 years.

Why the change in numbers?

Until now, the official figure was 64 - even though the island had previously acknowledged the death toll was probably much higher. In the wake of the disaster, some experts estimated as many as 4,600 deaths.

The government's initial number was arrived at by counting those crushed by collapsing structures, drowned and hit by flying debris.

The latest findings—accepted by the island’s authorities—were made in a report by experts from George Washington University, which the governor commissioned.

"This shows the magnitude of the catastrophe," Governor Rossello told newspaper El Nuevo Dia.

When asked why his government was unable to recognise a higher death toll, he replied: "I am not perfect. I make mistakes. Now, hindsight tends to be 20-20."

Lacked Awareness

He echoed one finding in the report - that doctors "lacked awareness" on how to appropriately certify deaths attributed to natural disasters.

"The responsibility for adjudicating the cause of deaths rested with the doctors," Mr Rossello told the island's most circulated paper. "But unfortunately there was no formal process to prepare them for this kind of devastation.

"At that moment, that was the number [of deceased] that we had and today we have the evidence which indicates the number was definitely higher."

What does the report say?

Researchers tracked the number of deaths using death certificates and other mortality data between mid-September 2017 to mid-February of this year.

Many people died as a result of poor healthcare provision and a lack of electricity and clean water. Repeated power outages also led to an increased number of deaths from diabetes and sepsis.

The Caribbean island is home to 3.3 million US citizens, some 8% of which have since left the island, the study said.

It also said that those from poorer backgrounds in Puerto Rico were 45% more likely to have been killed in the aftermath of the hurricane.

The governor said he would sign an executive order to create a committee to examine and put into practice the report's recommendations.

Is this controversial?

Puerto Rico has been reeling ever since this devastating storm hit its shores - with residents still suffering blackouts, broken infrastructure and a lack of services.

Hurricane Maria caused the largest blackout in US history, according to research consultancy the Rhodium Group.

It is ranked as the third most financially costly cyclone in US history since 1900, yet its death toll is a third higher than the costliest - Hurricane Katrina in 2005, with an estimated 1,833.

The new study raises questions about US President Donald Trump's response to the disaster.

During a visit in October, Mr Trump had suggested officials should be "proud" the death toll - at the time only 16 - was not as high as "a real catastrophe" like Katrina.