New York state has eased its controversial quarantine rules for how those arriving from Ebola-stricken West Africa must be treated.
It has ended the mandatory 21 day isolation period for people who had no contact with an infected patient.
New York, New Jersey and Illinois have drafted in measures that see health care workers returning from West Africa - epicentre of the most deadly Ebola outbreak on record - quarantined for three weeks, while a fourth US state, Florida, has ordered twice-daily monitoring during that period.
But under pressure from the White House, where officials believe these rules could deter health workers from helping fight the epidemic in West Africa, New York Governor Andrew Cuomo rushed to ease his state's Ebola-clearance procedures.
Cuomo said late on Sunday that there would no longer be a blanket quarantine procedure from all people entering the state from affected countries in West Africa.
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Instead, if someone arrives from an affected area with no symptoms and without having had direct contact with people infected with Ebola, no home confinement will be required.
Meanwhile health officials will monitor these travellers twice daily for temperature and other symptoms until the 21-day incubation period has expired.
For those who have had contact with Ebola-infected people in West Africa but are not showing symptoms themselves, Cuomo said his state now will require them to be confined to home for three weeks.
Health Department officials will transport them and monitor their health daily throughout the isolation period, he said.
Earlier, New York City Mayor Bill de Blasio sounded defiant as he gave no indication he planned to bow to White House pressure.
Kaci Hickox, who became the first American health worker isolated under the new quarantine orders on Friday, claims she was made to feel like a criminal and that her compulsory quarantining was "inhumane."
De Blasio attempted to quell the firestorm over Hickox's outspoken remarks, in which she hit out at officials' attitude toward her from the moment she landed at Newark International Airport on Friday.
"This hero was treated with disrespect, was treated with a sense that she had done something wrong, when she hadn't; was not given a clear direction," de Blasio told a press conference.
"We owe her better than that and all the people better than that."
Health authorities have also expressed concern that the strict new rules will discourage badly needed health workers from volunteering in West Africa, where more than 4,900 people have already died of the hemorrhagic Ebola virus.
US President Barack Obama's administration has urged the governors of New York and New Jersey to reverse the quarantine rules, The New York Times reported.
