The USNS Comfort arrived in Manhattan on Monday and will treat those who need non-coronavirus related care.
Despite the lockdown in effect, groups of people gathered to watch the ship arrive, likely breaking social distancing rules.
Mayor of New York, Bill de Blasio recently announced that he would fine people $500 for not practising social distancing.
The ship will free up space in New York hospitals, allowing medical officials to focus on tackling Covid-19.
New York is currently struggling with the outbreak, having reported the most cases of any state in the US.
Figures from the Johns Hopkins University show that New York has upwards of at least 1000 deaths related to the virus.
The ship is equipped with 12 operating rooms, a laboratory, a pharmacy and will be used immediately to treat patients.
The governor of New York, Andrew Cuomo, released a video on Twitter explaining how helpful the ship will be.
In the video, Mr Cuomo lists the medical capabilities of the ship and says: “we are going to fight every way we can to save every life that we can”.
Some Twitter users criticised the crowd that gathered to watch the ship come in, amid repeated warnings about social distancing.
Twitter user @achorowitz tweeted: “You would think the necessity of a gigantic hospital ship would be enough to make people rethink crowd situations but... *gestures wildly*.”
Another user, @juliakmarsh highlighted the Mayor’s policy, posting: “De Blasio said this morning he’d start fining people up to $500 for not social distancing yet there’s this crowd outside Pier 90 where the US Naval Hospital Ship Comfort and none of the several cops on site are doing anything to disperse them.”
Mr de Blasio commented on the ship’s arrival, saying: “This is like adding another hospital here in New York City”.
Mr Cuomo extended his executive order on Sunday, stating all non-essential workers must stay home for another two weeks as coronavirus cases increase.
In a press conference on Sunday evening Mr Cuomo said: “This is not a lockdown. It is a travel advisory to be implemented by the states, in essence.”
“It’s nothing that we haven’t been doing, right? Non-essential people should stay home.”
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