Nearly $1.0 billion dollars is needed to fight the Ebola outbreak raging in west Africa, the United Nations said Tuesday, warning that 20,000 could be infected by year end.
UN humanitarian chief Valerie Amos said there was a ?huge funding challenge?.
?If not dealt with effectively now, Ebola could become a major humanitarian crisis in countries currently affected,? she told reporters in Geneva.
The capacity of Guinea, Sierra Leone and Liberia to provide even the most basic necessities was, she warned, ?on the brink of collapse.?
US President Barack Obama was set Tuesday to announce US efforts to ?turn the tide? in the Ebola epidemic, with plans to order 3,000 US military personnel to west Africa.
US advisors will also train up to 500 health care providers per week in Liberia, according to the plan Obama was set to unveil in Atlanta.
The United Nations said the response to the crisis will require $987.8 million (763 million euros), with about half needed for the worst-hit country, Liberia.
Its announcement comes amid mounting global alarm over the worst-ever Ebola epidemic, which by Friday had claimed 2,461 lives out of 4,985 cases, according to fresh numbers from the World Health Organization.
The UN document estimates that some 20,000 people could be infected with Ebola by the end of the year, with Guinea accounting for 16 percent of infections, Sierra Leone 34 percent and Liberia a full 40 percent.
If the international community and affected countries respond swiftly and energetically, transmission should begin to slow by the end of the year and halt by mid-2015, the document said.
- ?Unprecedented? surge needed -
Countries have in recent days been scambling to boost aid, with the European Union lamenting Monday that too much ?precious time was lost.?
?The level of surge we need to do is unprecedented. It is massive,? the UN?s Ebola coordinator David Nabarro told reporters.
Adding to international efforts, China will also send a mobile laboratory team to Sierra Leone, where more than 500 people have died so far from Ebola.
The 59-person team from the Chinese Centre for Disease Control will include epidemiologists, clinicians and nurses, and will bring the number of Chinese medics in the country to 174, WHO said Tuesday.
The EU, Britain, France and Cuba have also pledged to send medical teams and other aid to the region.
But this is far from enough, warned Joanne Liu, head of the Doctors Without Borders (MSF) charity.
Pointing out that the known Ebola cases ?represents only a fraction of the real number,? she stressed that ?the ground response remains totally and lethally inadequate.
- Window of opportunity closing -
?The window of opportunity to contain this outbreak is closing,? she told Tuesday?s meeting of UN agencies, member states and other actors involved in the Ebola fight.
WHO emergency chief Bruce Aylward agreed.
?This health crisis we face is unparalleled in modern times,? he said Tuesday.
?We don?t know where the numbers are going,? he said, pointing out that two weeks ago when WHO said it needed the capacity to manage 20,000 cases, ?that seemed like a lot.?
?That does not seem like a lot today,? Aylward said.
He stressed the difficulty of estimating accurately how many people might become infected and die going forward.
?The numbers can be kept in the tens of thousands, but that is going to require a much faster escalation of the response if we?re to beat the escalation of the virus,? he said.
Liu meanwhile warned that Ebola was affecting far more than the people infected with the disease.
?While thousands have died of Ebola, many more are dying from easily treatable conditions and diseases because health centres no longer function,? she said.
?States have a political and humanitarian responsibility to halt this mounting disaster,? she said. ?The clock is ticking.?
WHO said Tuesday it this week was reconvening its emergency committee in Geneva which declared the outbreak an international health emergency in August, to consider further measures to limit its spread.
The UN Security Council will meanwhile hold an emergency session Thursday to discuss ways to ramp up the global response to the epidemic.
The Ebola virus can fell its victims within days, causing severe fever and muscle pain, weakness, vomiting and diarrhoea ? in some cases shutting down organs and causing unstoppable bleeding.
No licenced vaccine or treatment exists but health experts are looking at fast-tracking two potential vaccines and eight treatments, including the drug ZMapp.