New York state on Sunday relaxed its rules for how people arriving from Ebola-stricken West Africa must be treated, ending a mandatory isolation period for even those 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 -- epicenter 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.
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.
After Obama's meeting with his public health and national security aides Sunday, the White House said in a statement their moves were not the best choices.
US measures, it said, "must recognize that health care workers are an indispensable element of our effort to lead the international community to contain and ultimately end this outbreak at its source, and should be crafted so as not to unnecessarily discourage those workers from serving."
US envoy hits out at global response
The US ambassador to the United Nations has criticised the level of international support for nations hit by Ebola as she begins a tour of west African nations at the epicentre of the deadly outbreak.
Samantha Power said before arriving in Guinea on Sunday that too many leaders were praising the efforts of countries like the United States and Britain to accelerate aid to the worst-affected nations, while doing little themselves.
"The international response to Ebola needs to be taken to a wholly different scale than it is right now," Power told NBC News.
She said many countries "are signing on to resolutions and praising the good work that the United States and the United Kingdom and others are doing, but they themselves haven't taken the responsibility yet to send docs, to send beds, to send the reasonable amount of money."
Besides Guinea, Power will travel to Sierra Leone and Liberia -- the three nations that account for the vast majority of the 4,922 deaths from the Ebola epidemic.
More than 10,000 people have contracted the virus in west Africa, according to the latest World Health Organization figures.
Another country in the region, Mali, is scrambling to prevent a wider outbreak after a two-year-old girl died from her Ebola infection following a 1,000-kilometre (600-mile) bus ride from Guinea. She was Mali's first recorded case of the disease.
Ebola can fell its victims within days, causing severe fever and muscle pain, weakness, vomiting and diarrhoea -- in some cases shutting down organs and causing unstoppable bleeding.
The tropical virus is spread though close contact with the sweat, vomit, blood or other bodily fluids of an infected person. No widely-available medicine or vaccine exists.