Amid mounting fear of the spread of Ebola, western countries scrambled to put airport security measures in place.
New measures to screen travelers for the deadly virus were being considered as the United Nations made an urgent appeal for cash after getting merely $100,000 for a crisis fund to tackle the deadly epidemic.
US lawmakers grilled officials over how an infected nurse was allowed to board a crowded flight, and European officials promised a review of how passengers from Ebola-hit countries are screened.
UN Secretary General Ban Ki-moon said the call for donations to a UN trust fund had fallen on deaf ears and left them with "a very serious problem" as experts warn that the death toll from the disease may be about to spiral.
Despite $20 million of pledges, there was only $100,000 in the reserve fund -- reportedly donated by Colombia -- he told reporters in New York.
With only a quarter of the UN's overall $1 billion Ebola target pledged, Ban praised the US, Britain and France, but said other countries need to do their share. "Now it is time for other countries that have capacity... to provide financial support and other logistical support."
"We need to turn pledges into action. We need more doctors, nurses, equipment, treatment centres and medical evacuation capacities."
- Stinging criticism -
His predecessor Kofi Annan was even more stinging in his criticism of the world's response, charging that wealthy countries were slow to tackle the crisis because it began in Africa.
"If the crisis had hit some other region it probably would have been handled very differently," the Ghanaian diplomat told the flagship BBC programme Newsnight.
"In fact when you look at the evolution of the crisis, the international community really woke up when the disease got to America and Europe."
Ban said an increase in donations was crucial, with fears growing of a spread beyond Africa as the death toll nears 4,500.
"I appeal to the international community to provide the $1 billion that will enable us to get ahead of the curve and meet our target of reducing the rate of transmission by December 1," he said.
By some counts donors have given almost $400 million to other UN agencies and aid organisations to fight Ebola, with the UN trust fund needed as a flexible fall-back to deal with emergency situations.
France and Spain placed several potential victims under observation and in Liberia, the worst hit country so far, the minister of transport placed herself in quarantine after her driver died.
EU health commissioner Tonio Borg said the bloc would review exit screening of travellers from Liberia, Guinea and Sierra Leone, in coordination with the WHO.
And EU health ministers, meeting in Brussels, agreed to coordinate measures at entry points to the 28-member Union.
Meanwhile, in Africa the World Health Organization (WHO) vowed to ramp up its efforts to help 15 countries defend themselves against the virus.
A string of health workers have been evacuated back to Europe from Africa with Ebola, but the only confirmed case of transmission on the continent so far is a Spanish nurse in Madrid.
- Authorities embarrassed -
Doctors in Spain have identified six more cases of possible infection, including a missionary priest who recently returned from Liberia and has shown signs of fever. Two tested negative for the disease, officials said Friday.
And in France, a nurse who had earlier helped treat a returning Ebola patient was taken to a military hospital with what an official called a "suspect fever" -- though initial tests for the virus also came back negative.
In the United States, two nurses who treated a Liberian traveller have now fallen ill, to the embarrassment of health authorities, who faced questioning about how the disease had spread.
The first of them, Nina Pham, was transferred from Texas to the National Institutes of Health outside Washington late Thursday.
In a brief video taken earlier while she was in Texas, Pham looked lucid and smiling as she spoke to her doctor.
"I love you guys," an emotional Pham says, as she wipes away tears.
Pham and the second infected US nurse were involved in the care of a Liberian man, Thomas Eric Duncan, who died on October 8, the first Ebola case diagnosed in the United States.
As of Sunday, 4,493 people had died out of a total of 8,997 cases in the outbreak, according to the WHO, which has warned that the infection rate could reach 10,000 a week by early December.