US President Donald Trump said Saturday he is weighing placing a two-week quarantine on New York and nearby states, the US epicenter of coronavirus infections, to slow the spread of the disease to other parts of the country.

The harshest measure yet by the US government in the face of the coronavirus pandemic could isolate over 10 million people in the country's most densely populated region, and would come as total infections across the country have passed 115,000.

Trump indicated he could make a decision later Saturday, even as New York Governor Andrew Cuomo said Trump hadn't mentioned the idea in a phone call earlier in the day.

"There's a possibility that sometime today we'll do a quarantine -- short-term, two weeks -- on New York, probably New Jersey, certain parts of Connecticut," he said as he left the White House.

The measure would be aimed at restricting travel from the crowded region to other parts of the United States, especially the southern state of Florida, a popular winter destination for New Yorkers and others in the northern part of the country.

Trump himself has residences in New York and Florida.

"Because they're having problems down in Florida. A lot of New Yorkers are going down. We don't want that. Heavily infected," Trump said.

Later the US leader confirmed the idea on Twitter. A decision "will be made, one way or another, shortly," he said.

US epicenter

The New York area has been the most seriously hit by  COVID-19 in the United States, with more than 52,000 cases in New York state.

Cuomo said a quarantine had not come up in his talks with Trump Saturday morning. 

"I don't even know what that means," Cuomo told a press briefing.

"I don't know how that could be legally enforceable. And from a medical point of view, I don't know what you would be accomplishing," Cuomo said.

"But I can tell you, I don't even like the sound of it. Not even understanding what it is, I don't like the sound of it," he said.

The number of COVID-19 infections in Florida is much lower than New York, topping 3,700 Saturday according to USA Today.

On Wednesday, Florida Governor Ron DeSantis issued an executive order mandating two-week  self-quarantines for anyone arriving or recently arrived from New York.

On Friday he made the same order for people coming from Louisiana, another coronavirus hotspot, and said police will put up checkpoints along the state line.

He also announced a two-week suspension of vacation rentals in Florida to discourage visitors.

"All we are trying to do is keep our residents here safe. If you are coming from one of the epicenters... don't come here because we are trying to protect our folks," he said.

'That's nuts'

But with coronavirus in all 50 states, experts said a quarantine on an area as large as the New York-New Jersey-Connecticut region might not be as useful as other more targeted measures.

Kent Sepkowitz, an infectious disease expert with the Memorial Sloan-Kettering Cancer Center in New York, told CNN it would not really work.

"Certainly it does not help New York do anything. It cuts us off from everyone else," he said.

"But the virus is all over the country now... So the notion that we can sort of blame New York and wall it off, and build a wall around Manhattan, that's nuts."