Canada says it will donate up to 1,000 doses of an experimental Ebola vaccine to help battle the diseaseâ€™s outbreak in West Africa.
It comes after the World Health Organization said it was ethical to use untested drugs on Ebola patients.
However, experts say supplies of both the vaccine and the experimental drug Zmapp are limited and it could take months to develop more supplies.
More than 1,000 people have been killed by the current outbreak
Canada says between 800 and 1,000 doses of the vaccine, which has only been tested on animals, will be donated to the World Health Organization (WHO) for use in West Africa.
However, it will keep a small portion of the vaccine for research, and in case it is needed in Canada.
The current outbreak has infected people in Guinea, Sierra Leone, Liberia and Nigeria.
Dr Gregory Taylor, deputy head of Canadaâ€™s Public Health Agency, said he saw the vaccines as a â€œglobal resourceâ€.
He said he had been advised that it would make sense for health care workers to be given the vaccine, given their increased risk of contracting the disease.
Even if Canada releases most of its existing doses, experts warn it could take four to six months to make a quantity large enough to have any real impact at preventing the illness, the BBCâ€™s Lee Carter reports from Toronto.
On Tuesday, the WHO said that in light of scale of the outbreak and high number of deaths, it was â€œethical to offer unproven interventions with as yet unknown efficacy and adverse effects, as potential treatment or prevention.â€
Last week the WHO declared the Ebola outbreak was a global health emergency.