Speaking in Sydney ahead of the G20 Finance Ministers and Central Bank Governors in Cairns this weekend, Dr Kim said there was a four- to six-month window to control the outbreak, which has killed more than 2600 people.

"If we don't do it in the next four to six months and it spreads to 15 or 20 countries, the impact will be frightening," he said.

Analysis by the World Bank shows the economic impact of the Ebola emergency could grow eight-fold next year if the outbreak is not contained. Dr Kim said the cost could rise into the "many billions" if the emergency spreads to more countries.

"If we don't get it under control, if the response falls apart, then it really could be a risk for the entire world," he said.

"The good news is we have all the tools to get it under control and I'm optimistic we will do that."

On Wednesday Foreign Affairs Minister Julie Bishop said the government would provide a further $7 million to support the international response to the Ebola outbreak in West Africa, bringing its total commitment to $8 million.

But medical NGO Medecins Sans Frontieres immediately called for Australia to "go beyond" just pledging money and deploy specialised civil and military personnel to affected countries in West Africa – a call backed by Australian Medical Association president Brian Owler on Friday. "There are people available but they need the back-up and support of the government," he said.

MSF says it cannot accept funds from the Australian government but is instead asking nations to evaluate their capacity to make a contribution beyond financial support.

"Donating to organisations such as Medecins Sans Frontieres is not the best way for governments to meet the immediate needs," said Paul McPhun, executive director of MSF Australia.

Mr McPhun said it was "unacceptable" that MSF, a single NGO,  was providing the bulk of isolation units and beds in response to the emergency.

"What is needed is a massive increase in personnel, equipment and logistical support that Medecins Sans Frontieres alone cannot supply," he said.

Dr Kim said he was "very grateful" to nations that have sent personnel to help combat the Ebola emergency.

The epidemic continues to spread rapidly in Guinea, Liberia and Sierra Leone, with the World Health Organisation projecting that the virus could infect more than 20,000 people.

The US response to the Ebola outbreak was increased dramatically this week when President Barack Obama announced the deployment of 3000 US military personnel and a $US500 million ($558 million) boost in aid to affected countries.

The World Bank Group is mobilising a $230 million financing package for the three countries hardest hit by the Ebola crisis, which will help contain the spread of infections, help communities cope with the economic impact of the crisis, and improve public health systems throughout West Africa.

Earlier this week the UN Security Council declared the Ebola outbreak a "threat to international peace and security" and unanimously adopted a resolution calling on member states to provide more resources to combat the emergency.

Council members heard that the international response would need to be 20 times greater than it was now, if the outbreak were to be controlled.