World leaders have declared the Ebola outbreak the worst global health emergency in years amid stark warnings that the virus, which has killed nearly 4500 people, was spreading.
US President Barack Obama on Wednesday called on the world to do more, while insisting his own country would be "much more aggressive" in its response, after a second Texas hospital worker tested positive.
The fact that the newly infected Dallas caregiver took a domestic flight one day before she was quarantined magnified global fears about air travel - concerns Obama tried to tamp down after national crisis talks.
"We are going to have to make sure that we do not lose sight of the importance of the international response to what is taking place in West Africa," Obama said after meeting with his top advisers on Wednesday.
"If we are not responding internationally in an effective way ... then we could have problems."
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Earlier, Obama called his counterparts from Britain, France, Germany and Italy to better co-ordinate their plan to combat the outbreak.
"Leaders agreed that this was the most serious international public health emergency in recent years and that the international community needed to do much more and faster," British Prime Minister David Cameron's office said.
Obama urged Cameron, Germany's Chancellor Angela Merkel, France's President Francois Hollande and Italian Prime Minister Matteo Renzi to "make a more significant" contribution to the fight, the White House said.
European Union health ministers are to meet in Brussels on Thursday, with member states under pressure to follow Washington in sending troops to West Africa to help fight the virus.
Leaders of Latin American and Caribbean countries will meanwhile hold a summit in Havana on Monday to prepare their response to preparedness eventual Ebola cases in the region.
Meanwhile, airports in Britain, France, Canada and the US have already introduced stepped-up screening of travellers arriving from West Africa.
On Thursday, additional screening measures are due to launch in the United States at Newark's Liberty, Chicago's O'Hare, Atlanta's Hartsfield, and northern Virginia's Dulles, the White House said. Last week, screening started at New York's JFK International.
The worst Ebola outbreak on record has so far claimed 4493 lives, out of 8997 recorded cases, according to the World Health Organisation.
The haemorrhagic virus has ravaged West African countries Liberia, Guinea and Sierra Leone since the start of the year, and the UN health agency has warned there could be a steep rise in infections in coming months.
In Liberia, the country worst hit by the crisis, hard-pressed doctors and nurses returned to work after a two-day strike to demand hazard pay for dealing with Ebola patients.
The US pledged $US5 million ($A5.41 million) to help pay the workers, many of whom have caught the virus from their patients, bringing its total commitment to the country to $US142 million, Liberian officials said.
Meanwhile, the US Centres for Disease Control and Prevention (CDC) issued an alert for all passengers who travelled on an October 13 flight from Cleveland, Ohio to Texas.
Authorities want to interview 132 people who flew on a plane with an Ebola-infected nurse - the second American to be infected within the US - who had not yet become symptomatic.
The woman was isolated at Texas Health Presbyterian hospital in Dallas late on Tuesday with a fever, and the crew on the flight said she had not been symptomatic when she flew a day earlier.
Both women infected in Texas treated a Liberian Ebola patient, Thomas Eric Duncan, who died in Dallas on October 8.
