Even as Sierra Leone quarantined one million people in a desperate bid to combat Ebola, world leaders were asked to pledge urgently needed aid to battle the disease in West Africa .
US President Barack Obama warned that not enough was being done to tackle the crisis that has left close to 3,000 dead and is spreading at an alarming pace.
"We are not moving fast enough. We are not doing enough," Obama told a meeting at the United Nations.
"Right now, everybody has the best of intentions, but people are not putting the kinds of resources necessary to put a stop to this epidemic."
The meeting was called by UN Secretary General Ban Ki-moon to ramp up the international response after the Security Council last week declared the outbreak a threat to world peace and security.
Health systems in the worst-hit countries of Liberia, Sierra Leone and Guinea have been overwhelmed and the United Nations has repeatedly appealed for more doctors, nurses, medical equipment and supplies to be sent to West Africa.
Sick patients are being turned away from health centers due to the lack of beds and families are traumatized by medical orders to pull away from sick relatives.
"The world can and must stop Ebola now," Ban said in his address to the meeting. "Today, it is time for the international community to step up."
Sierra Leone on Thursday took the drastic step of putting more than one million people in five districts under quarantine-- the largest open-ended lockdown in the Ebola outbreak.
The northern districts of Port Loko and Bombali have been closed off indefinitely along with the southern district of Moyamba -- effectively sealing in around 1.2 million people.
With the eastern districts of Kenema and Kailahun already under quarantine, more than a third of the population of six million -- in five of the nation's 14 districts -- now finds itself unable to move freely.
- 'Enemy disease' -
"My country is at the battlefront of one of the biggest life and death challenges facing the global human community," Sierra Leone's President Ernest Bai Koroma told the meeting by video link from Freetown.
"Ebola is not only a disease of Sierra Leone and its neighbors, it is a disease of the world."
President Ellen Johnson-Sirleaf of Liberia, the worst-hit country, thanked donors in an address by video-link from Monrovia, and vowed: "We are fighting back."
The Liberian president recalled that her country was emerging from years of conflict and that the epidemic threatened to wipe out peace gains.
"Today, we face perhaps the greatest challenge, for we cannot allow the projection of a worst case scenario that over 100,000 of our innocent citizens will die from an enemy disease they do not understand," she said.
Canada announced it will contribute $27 million dollars to the effort and France said it has set aside 70 million euros in a battle that the United Nations estimates will require close to one billion dollars.
The United States is sending 3,000 troops to Liberia to help health workers battle the contagion and has mobilized its experts from the Centers for Disease Control and Prevention to help beat back the virus.
The CDC estimates that cases in Liberia and Sierra Leone could rocket to 1.4 million by January -- in a worst-case scenario based on data obtained before the world ramped up its response.
- 'Potential meltdown' -
World Bank president Jim Kim said the "spread, the magnitude and the complexity of the Ebola crisis is like nothing we have ever seen before" and warned that it could lead to the "potential meltdown of the continent."
The World Bank warned in a recent report of potentially catastrophic economic losses from the outbreak and pledged $400 million to fight the outbreak.
The virus can fell its victims within days, causing rampant fever, severe muscle pain, vomiting, diarrhea and -- in many cases -- unstoppable internal and external bleeding.