A powerful tropical storm that hit Puerto Rican territory last week has left at least $1 billion in damage, officials said.
The storm left hundreds of homes without power and caused widespread flooding.
“Today we will not be able to estimate the total damage caused by the storm, but we can tell you that at least about a third of the island is without electricity,” Puerto Rico governor Ricardo Rosselló said on Twitter on Monday.
He said that some of the damage could reach $5 billion.
“The devastation in Puerto Rico is unprecedented,” he said.
Rossello said the hurricane had left at most about 300,000 people without power in the island’s capital, San Juan.
A senior official in Puerto Rican state-owned electricity company said the island could suffer more than 300,00 people without electricity by Monday evening.
The official said the total amount of power lost by Puerto Rico and Puerto Rico’s territory was about $2.4bn.
The disaster was sparked by an unusually strong Category 5 storm, the strongest storm to hit the US territory in recent years.
It made landfall about 25 kilometres (15 miles) from the island on Friday.
It caused a storm surge of up to 9 metres (33 feet) in parts of Puerto Rico, where it caused widespread power outages.
Officials said that the storm also caused damage to about 50 buildings on the island.
The governor of Puerto Rican island of Puerto Luzon, Ricardo Rosales, said that Puerto Rico was also affected by the hurricane and that his office was working with US federal agencies.
“We need to prepare for the worst.
There is a lot of damage, and a lot is missing,” he told reporters in Puerto Luzón.
Rosales said the US was sending more than 100 personnel to Puerto Rico to assist in restoring power.
Maria is the strongest hurricane to reach Puerto Rico in 20 years.
Rosalsaid the storm hit at the height of the rainy season, which typically starts in May.
The Category 5 hurricane was initially thought to be the strongest on record, with winds reaching 160 kilometres per hour (100 mph), according to USGS data.
But its strength dropped to 160 kilometres (100 miles) per hour by Sunday afternoon, as a strong trough moved over Puerto Rico.
“This storm was an unprecedented event,” said Dan Ostroff, a meteorologist at the US National Hurricane Center.
“If you take into account that it was so strong, and it was going at such a fast rate, then the chances that it could hit the mainland really were very slim.”
The storm is forecast to intensify in coming days and is expected to bring sustained winds of up 80 kilometres per hours (50 mph) in Puerto Ricans south-east coast and 80 kilometres (50 miles) in the central part of the US island.
Hurricane Maria made landfall in Puerto Vallarta, on the US state’s southern tip, on Friday and is now the fourth strongest hurricane on record.
It was initially expected to weaken, but has since strengthened again.
Puerto Rico has suffered heavy damage from the storm.
A large area of the territory’s main island has been flooded by rain and mud and the governor said that more than a third the population had been left without power.
A second wave of damage was expected in the coming days, and Rosales warned that more storm surges were possible in the weeks ahead.
“I can assure you that the hurricane will make Puerto Rico a bigger island, and the storm will continue to make it a bigger city,” he added.
Roslandas warning came amid a record-breaking summer of severe weather in the US.
More than three million people have been left homeless in the aftermath of Hurricane Maria, which left thousands of homes and businesses without power across the Caribbean, according to the US Government Accountability Office (GAO).
“It’s been a difficult, expensive year for Puerto Rico,” Rosales told reporters on Monday, adding that the island was “still hurting”.
He said the number of people who have sought refuge in shelters was increasing rapidly.
The government has appealed for donations of food and other essentials in an attempt to rebuild.
The hurricane also damaged hundreds of power lines in the capital of San Juan, Puerto Rico Governor Ricardo Rosas told reporters.
“It is not a good time for us to go back to the days when we were on a strong path, when we could rebuild,” Rosas said.
“Now is not the time.”
He added that the government was working to restore power to Puerto Ricos most vulnerable citizens and was looking for more donations.
“That is our priority,” Roses said.
Puerto Rican authorities said on Monday that about a quarter of the islands population was without power, which is likely to cause further hardship.