World Bank President Jim Yong Kim warned Friday that the Ebola epidemic is "not close to being over" after a new front opened against the deadly disease in Mali.

"Our end game is not near," Kim said at a summit on Ebola with the leaders of the United Nations, World Health Organization and the International Monetary Fund.

""We must get to zero cases. Ebola is not a disease where you can leave a few cases and say you've done enough."

Kim, UN chief Ban Ki-moon and WHO chief expressed deep concern that the outbreak has not been contained despite gains in Liberia and Guinea, two of the three countries in which infections have been concentrated.

"International support is making a difference. But there's also evidence that is very worrisome, such as the increase in infections in Sierra Leone and the spreading of the outbreak to Mali," Kim said.

The newest outbreak of Ebola surfaced early this year and has since killed nearly 5,500 people, according to WHO.

In Mali seven people have died in recent weeks, most linked to contact with a single infected 70-year-old Grand Imam from Guinea, who died in a Bamako clinic on 27 October.

WHO Director General Margaret Chan, who was at the Washington summit, and Michel Sidibe, executive director of UN AIDS, were to leave for Mali on Friday to help organize disease control efforts.

"The Ebola virus is a formidable enemy," Chan said.

"We have to really move with speed and scale and have a no-regret policy. We must smother a little fire, a little smoke before it gets out of control."

She expressed confidence that the outbreak could be brought under control, adding though that "We must maintain our vigilance... We need to continue to do more to get to zero."

As recently as early October the leaders had expressed hopes that the Ebola epidemic could be controlled by the end of the year.

The World Bank has mustered $1 billion to be used in social relief for infected populations and support for local and international health workers involved in the fight.

The International Monetary Fund has allocated $430 million in financial relief, focused on helping governments stay afloat as commerce, industry and agriculture activity has sharply contracted in the three most affected countries.

But the UN's Ban said Friday that they now expect it will take through the first half of 2015 to control the epidemic.

"If we continue to accelerate our response, we can contain and end the outbreak by the middle of next year," he said.

Even so, he added, "The consequences of Ebola will long outlast the outbreak."