He also said the Democrats were "trying to make [him] look bad" by reporting the high numbers of deaths.
"If a person died for any reason, like old age, just add them onto the list", said Trump, attempting to dismiss the long-term effects of the disaster, where the island was without electricity and water for months, as the administration struggled to restore power. "When I left the Island, AFTER the storm had hit, they had anywhere from 6 to 18 deaths".
The report came almost a year after a much-maligned visit to Puerto Rico by Trump two weeks after Maria, where he implied that residents should be "proud" that the official death toll at the time was just 16 people, far lower than that of a "real catastrophe, like Katrina". "Then, a long time later, they started to report really large numbers, like 3,000".
'This is what denial following neglect looks like: Mr Pres in the real world people died on your watch. Wednesday, Trump called her "totally incompetent" when he tweeted another defense of how the emergency was managed.
Initial death tolls for Maria were set at 64, but many observers expressed doubts at that number as the territory's medical and transportation infrastructure was insufficiently prepared for the storm. Bad politics. I love Puerto Rico!'
"That's the official death toll, you lunatic!"
If the new figures are accurate, Hurricane Maria is the deadliest storm to have hit Puerto Rico since the 1899 San Ciriaco hurricane.
A team of researchers at Harvard University announced in May that they believed Hurricane Maria's death toll was 4,600.
San Juan Mayor Carmen Cruz responded to Trump's comments Thursday morning in a series of messages on Twitter. It made landfall on Puerto Rico on September 20, battering the island with winds of up to 155 miles per hour, ripping buildings apart and uprooting trees.
Especially upset were GOP politicians in Florida, a state with a substantial Puerto Rican population.
The hurricane hit the Caribbean island last September.
South Carolina Sen. Lindsey Graham, a friend of Trump's who talks to him often, said he thinks Trump "sees every attack on him as sort of undercutting his legitimacy". A USA territory since 1898, Puerto Rico's inhabitants are citizens, though they can not vote in presidential elections and have only one congressional representative with limited voting powers.
"We left this analysis to the scientists and experts, recognising that there would be many challenges, because we wanted to have a powerful and independent voice to minimise the uncertainty", he said in a video on Facebook.