Liberia has set a national goal of having no new cases of Ebola by Dec. 25, President Ellen Johnson Sirleaf said in a radio address on Sunday, in a further sign that authorities believe they are getting on top of the virus.

Liberia is the nation hardest hit by the epidemic. At least 2,812 people have died in the West African country, out of a total of 5,165 victims in Liberia, Sierra Leone and Guinea, according to World Health Organization (WHO) data on Friday.

"We continue to combat the Ebola virus and strive to achieve our national objective of zero new cases by Christmas," Sirleaf said in an address that also announced a cabinet reshuffle.

Sirleaf named George Werner as health minister, a key position given the epidemic, to replace Walter Gwenigale.

The WHO said last week there were signs that the incidence of new cases is declining in Guinea and Liberia, although it reported steep increases in Sierra Leone.

The U.N. mission to combat Ebola has set a target of having 70 percent of patients under treatment by Dec. 1 and 70 percent of bodies safely buried by the same date.