Vice President Mike Pence tweeted that the CDC was urging residents of the three states "to refrain from non-essential travel for the next 14 days."
The notion of a quarantine had been advocated by governors, including Republican Gov. Ron DeSantis of Florida, who sought to halt travelers from the heavily affected areas to their states.
But it drew swift criticism from the leaders of the states in question, who warned it would spark panic in a populace already suffering under the virus. Trump announced he reached the decision after consulting with the White House task force leading the federal response and the governors of the three states. He said he had directed the Centers for Disease Control and Prevention "to issue a strong Travel Advisory, to be administered by the Governors, in consultation with the Federal Government." He added: "A quarantine will not be necessary."
On the recommendation of the White House CoronaVirus Task Force, and upon consultation with the Governor’s of New York, New Jersey and Connecticut, I have asked the @CDCgov to issue a strong Travel Advisory, to be administered by the Governors, in consultation with the....— Donald J. Trump (@realDonaldTrump) March 29, 2020
New York Gov. Andrew Cuomo, who has criticized the federal government's response as his state became the country's virus epicenter, said roping off states would amount to "a federal declaration of war."
He said he did not know what an enforceable quarantine means.
"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. But I can tell you, I just -- I don't even like the sound of it. I'm not even understanding what it is, I don't like the sound of it."
In comments later to CNN, Cuomo expressed strident opposition to any such action, calling it akin to what China did in Wuhan and a recipe for "total mayhem."
"I don't believe it would be legal. I believe it would be illegal," the governor said, suggesting a quarantine would further injure the hobbled economy and make the stock market "drop like a stone."
Cuomo said that he didn't believe the lockdown would be legal because of the interstate commerce clause.
The governor said that such a move would be completely against the actions thus far of the president, who Cuomo said has been working with state officials in response to the virus.
Earlier, the president also said this measure would restrict travel from "hot spots" around New York because "they're having problems down in Florida, a lot of New Yorkers going down, we don't want that."
Trump made his initial remarks while on a trip to Norfolk, Virginia, to see off a U.S. Navy hospital ship heading to New York City to help with the pandemic.
At the event, he spoke to a sparse crowd at the naval base and cautioned Americans to take virus protections, even though he himself, at 73, is in a high-risk category and among those who have been advised to refrain from all non-essential travel.
The federal government is empowered to take measures to prevent the spread of communicable diseases between states, but it's not clear that means Trump can ban people from leaving their state. It has never been tested in the modern era - and in rare cases when any quarantine was challenged, the courts generally sided with public health officials. Courts have ruled consistently for years that the authority to order quarantines inside states rests almost entirely with the states, under provisions in the Constitution ceding power not explicitly delegated to the federal government to states.
The federal government, though, would have power under constitutional clauses regulating commerce to quarantine international travelers or those traveling state to state who might be carriers of deadly diseases.
Still, "it is entirely unprecedented that governors or the president would prevent people from traveling from one state to another during an infectious disease outbreak," said Lawrence Gostin, a Georgetown University law professor and public health specialist who questioned Trump's ability to order a quarantine on states.
The governors of Florida, Maryland, South Carolina and Texas already have ordered people arriving from the New York area to self-quarantine for at least 14 days upon arrival. In a more dramatic step, Rhode Island police have begun pulling over drivers with New York plates so that the National Guard can collect contact information and inform them of a mandatory, 14-day quarantine.
Trump said the idea of isolating many in the trio of Democratic strongholds in the Northeast was pushed by DeSantis, one of the president's most outspoken supporters. It came a day after Trump made clear he wanted governors to be grateful when asking for federal support for the pandemic. Trump said people "go to Florida and a lot of people don't want that. So we'll see what happens." He later clarified it would not affect truckers or people transiting through, and would not affect trade.
Florida is a perennial swing state, and one Trump must win come November - plus he recently moved his residence from New York to Florida. It also has a population of 21 million with a large percentage of old people, who are particularly vulnerable to the virus. DeSantis confirmed he had spoken with the president about the possibility of a quarantine for the New York City area.
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