US President Barack Obama has said the international community must do more to help African nations struggling to control the Ebola outbreak.
At a crisis meeting in the White House, Mr Obama said the outbreak must be attacked at its source and warned that if it rages out of control in west Africa, it will spread globally.
He said federal officials would oversee the response to US Ebola cases in a more aggressive way and the Centers for Disease Control (CDC) would send a "SWAT team" to any hospital encountering a new case of the disease.
The meeting follows the confirmation that a second Texas nurse has tested positive for the disease, and that she travelled on a commercial flight the day before she presented with symptoms.
Amber Vinson came down with a fever yesterday and was immediately isolated at the hospital.
She is said to be ill but "clinically stable".
"Health officials have interviewed the latest patient to quickly identify any contacts or potential exposures, and those people will be monitored," the health department said in a statement.
The CDC confirmed that Ms Vinson travelled by air on a Frontier Airlines flight from Cleveland to Dallas-Fort Worth the day before she reported symptoms.
It has asked all 132 passengers on the flight to call a hotline.
Crew members on board said the nurse displayed no symptoms during the flight.
The CDC said it has identified three incidents of contact before Ms Vinson was placed in isolation.
CDC director Dr Thomas Frieden said the nurse should not have travelled on a commercial flight and "in future we will make sure others being monitored for Ebola will not be allowed to travel on a commercial flight".
Two nurses who cared for Thomas Duncan, who is thought to have contracted the disease while still in Liberia, and who died at Texas Presbyterian Hospital on 8 October, have now tested positive for Ebola.
Chronology: Worse Ebola outbreak on record
The CDC has already confirmed that the first nurse, Nina Pham, tested positive for the virus, despite wearing full protective gear while she cared for Mr Duncan.
Dr Frieden said a breach in safety protocols, possibly while removing protective gear, may have caused them to contract the virus.
Texas Presbyterian Hospital said it is in talks to transfer Ms Vinson to Emory University Hospital in Atlanta, where a number of US missionaries and health care workers were treated after contracting the disease in west Africa.
The hospital said on its Twitter feed that it is in consultations with Emory about transferring "our second co-worker being treated for Ebola."
President Obama said the likelihood of a widespread Ebola outbreak in the US is "very, very low".
UN calls on world to do more over Ebola outbreak
The UN Security Council called on the international community to "accelerate and dramatically expand" aid to combat the spread of Ebola.
In a unanimously adopted statement, the 15-member body warned that the world's response "has failed to date to adequately address the magnitude of the outbreak and its effects."
The council urged all member states and multilateral organisations to "accelerate and dramatically expand the provision of resources and financial and material assistance."
It called for mobile laboratories, field hospitals, trained clinical personnel, therapies, vaccines and diagnostics, and protective gear.
At the same time, it urged states as well as airlines and shipping companies to keep open trade and travel links with the West African countries most affected by the outbreak.
The latest death toll from the worst Ebola outbreak ever is 4,447, from 8,914 recorded infection cases.
The three hardest-hit countries are Liberia, Sierra Leone and Guinea.
"Ebola got a head start on us," said Anthony Banbury, head of the UN Mission for Ebola Emergency Response (UNMEER), earlier today.
"It is far ahead of us, it is running faster than us, and it is winning the race," he told the UN Security Council in New York, by remote link from UNMEER headquarters in Ghana.
"If Ebola wins, we the peoples of the United Nations lose so very much.
"We either stop Ebola now or we face an entirely unprecedented situation for which we do not have a plan."
He said that with infection rates rising exponentially every day, UNMEER will need 7,000 beds for treatment.
"There's much bad news about Ebola but the good news is we know how to stop it," Mr Banbury added.
However, to push back the spread "we must defeat Ebola and we must do it fast.
"With every day that passes, the number of sick people increases.
"Time is our biggest enemy. We must use every minute of every day to our advantage and that is what UNMEER is doing."
WHO assistant director general Bruce Aylward said the epidemic "could reach 5,000 to 10,000 cases per week by the first week of December", but described his figures as a working forecast.
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— European Commission (@EU_Commission) October 15, 2014