Leaders from the United Nations and the United States have called for "more robust" international efforts to tackle Ebola.
These calls came after medics in Liberia demanded danger money to treat patients in what officials termed the worst health crisis of modern times.
The call from US President Barack Obama and UN Secretary General Ban Ki-moon came as doctors and nurses in Liberia, one of the worst-hit countries, went on strike to demand higher pay to care for Ebola patients there.
Health care workers in west Africa are on the frontline of the Ebola outbreak -- branded by the World Health Organization as "the most severe acute public health emergency in modern times".
The epidemic has killed more than 4,000 people this year, mostly in Guinea, Sierra Leone and Liberia.
The Liberian walkout came as Obama spoke with Ban about the need for greater international efforts to fight the epidemic, with at least two cases of contamination reported beyond west Africa, in the US and Europe.
The two leaders called for "more robust commitments and rapid delivery of assistance by the international community", the White House said in a statement.
"Both leaders agreed that, given the threat posed by Ebola, at this crucial juncture members of the international community must redouble their resolve and commitment," the statement said.
The president also called on member states to "support the UN appeal and to provide the personnel, equipment and supplies required to stop the epidemic at its source."
Obama and his French counterpart Francois Hollande also issued a joint call for "stepped-up" global efforts to combat the disease.
- 'No-one taking care of us' -
In the face of panic that was "spreading faster than the virus", the WHO issued a stark warning over the crisis.
"I have never seen a health event threaten the very survival of societies and governments in already very poor countries," said WHO chief Margaret Chan in a statement delivered on her behalf at a Manila conference.
Ninety-five Liberian health workers have died so far in the epidemic, and their surviving colleagues want pay commensurate to the acute risk of dealing with Ebola, which spreads through contact with bodily fluids and for which there is no vaccine or widely available treatment.
In the Liberian capital Monrovia, a hospital patient quoted on local radio described scenes of desolation, with the sick deserted by striking staffers.
"We are at the Ebola Treatment Unit and no-one is taking care of us," the unnamed man said. "Last night several patients died. Those who can walk are trying to escape by climbing over the fence."
Journalists have been banned from Liberia's Ebola clinics, making the situation there difficult to ascertain.
The WHO's Chan has warned of "many more cases" to come for Guinea, Sierra Leone and Liberia without radical action by the international community.
- 'US must rethink approach' -
Both cases of contamination reported so far outside Africa -- in Spain last week and now in the United States -- have involved health workers who fell ill despite stringent safety protocols surrounding Ebola.
US health authorities said the United States must "rethink" its approach to Ebola after a female nurse in Texas contracted the tropical virus, in the first case of contamination on US soil and the second outside Africa.
Health authorities said the nurse -- identified by local media as 26-year-old Nina Pham -- tested positive after caring for a Liberian Ebola patient, Thomas Eric Duncan, who died on Wednesday.
The nurse at Texas Health Presbyterian Hospital in Dallas is in isolation and said to be in stable condition.
Experts still do not know exactly how the woman was infected, the Centers for Disease Control and Prevention said.
"We have to rethink the way we approach Ebola infection control because even a single infection is unacceptable," said CDC director Tom Frieden.
However, he gave few specifics about what precisely was going to change.
Meanwhile, Canada announced it would begin testing an experimental vaccine, VSV-EBOV, on humans. The first results will be available in December, according to Health Minister Rona Ambrose.
And European Union ministers called a meeting for Thursday to discuss screening travellers from west Africa, in line with steps taken by Britain, the United States and Canada.
In Spain, a crisis cell set up when Madrid nurse Teresa Romero fell sick after caring for two missionaries with Ebola said the nurse remained in a "very serious condition".
Fifteen other people are under observation in a Madrid hospital for symptoms of the disease, which include fever, diarrhoea, vomiting and bleeding.