Donald Trump has defended himself against criticism that his response to the natural disaster in Puerto Rico has been slow, saying that providing aid to the island isn’t as easy as helping out states in the contiguous US.

“It’s the most difficult job because it’s on the island, it’s on an island in the middle of the ocean,” Mr Trump said during a joint press conference with Spanish Prime Minister Mariano Rajoy. “It’s out in the ocean — you can’t just drive your trucks there from other states.”

“This isn't like Florida where we can go up the spine. This isn't like Texas where we go right down the middle and we distribute,“ Mr Trump said. ”This is a thing called the Atlantic Ocean. This is tough stuff.“

The majority of Puerto Rico has been without power since Hurricane Maria slammed into the US territory nearly a week ago, destroying infrastructure on the way. The storm brought in Hurricane Irma-level winds, and inundated the island with incredible flooding. Buildings were destroyed, communication lines were paralysed, and electricity was crippled, leaving most of the island without power.

But, although the island is facing a humanitarian crisis, and has already logged deaths as a result of strained resources, officials say that help has been slow to come. Food and medicine are becoming scarce on the island,and the devastation has been described as “apocalyptic” in areas.

“We need something tangible, a bill that actually answers to our need right now,” Puerto Rico Governor Ricardo Rossello said, urging Congress to act with an aid package. “Otherwise, there will be… a massive exodus to the [mainland] United States.”

So far, the US response has been to send supplies to Puerto Rico and the US Virgin Islands, and to send the National Guard to help stabilise the operations on the islands. The Coast Guard, according to an update from the Federal Emergency Management Agency, is helping to evaluate port safety so that ships can resume bringing in vital resources, and Red Cross volunteers are on sight to help with disaster response efforts.

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

Puerto Rico was already struggling with a massive debt burden that has led it to the brink of bankruptcy. The territory’s finances are under strict controls to pay off those debts, leaving it incapable of taking complete control of the financial resources it does have to respond to the crisis.

Mr Rossello was joined by several others in urging a swifter response to the crisis. Hillary Clinton urged the Defence Department to dispatch a medical ship to the island, and House Minority Leader Nancy Pelosi argued for a bipartisan relief package.

Florida Senator Marco Rubio, a Republican, has raised the alarm as well, saying that more people could die unless something is done to help the island.

“This has the potential of being a serious humanitarian crisis in a U.S. territory impacting United States citizens,” Mr Rubio told Politico before heading to say the same thing to Vice President Mike Pence. “There’s going to have to be a lot more hands-on federal engagement for us to be able to successfully carry out the mission.”

Mr Rubio warned that, without action, the US could be facing a Hurricane “Katrina-style” disaster in Puerto Rico.

Mr Trump, in the press conference, said that reviews of his response to Puerto Rico would mirror the mostly rosy marks he received for responding to natural disasters in Florida and Texas.

“We’ve gotten A-pluses on Texas, and on Florida, and we will also on Puerto Rico,” Mr Trump said. “But the difference is, this is an island. Sitting in the middle of the ocean. And, it’s a big ocean. It’s a very big ocean, and we’re doing a really good job.”