The WHO said the emergency needs a worldwide extraordinary response to bring a stop to the disease so it cannot spread any further.
Margaret Chan who is the head of the WHO, announced that the often deadly disease was spreading through nations that do not have resources to deal with it and requested international solidarity. Although, Chan acknowledged that a number of countries would likely not be affected by the outbreak.
The WHO issued an emergency warning that was similar in 2009 for the outbreak of the swine flu and in May of this year for polio.
Countries that are being affected now simply are not capable of managing an outbreak of such proportion and complexity by themselves.
She urged the entire international community to give support on the urgent problem.
Earlier in the week, the WHO organized a committee of medical experts to establish the Ebola outbreak gravity, which started in Guinea and has spread to Sierra Leone a neighbor as well as Liberia.
The death toll is said to stand at more than 900 people. In just a three-day period in early August, more than 108 new cases along with 45 deaths were confirmed from Liberia, Guinea, Nigeria and Sierra Leone.
The complete number of confirmed cases is now at 1,700 with a rate of fatality of close to 50%.
Last week Chan, had a meeting with the presidents of the countries affected and launched a joint response plan of $100 million to attempt to reign in the disease.
In the U.S., the Center for Disease Control raised the Ebola response on Thursday to its highest level and has recommended against traveling to West Africa.
Currently no licensed treatment of vaccine exists for the disease. Two medical missionaries from the U.S. were infected with the virus and are currently being treated in the U.S. with experimental drugs and appear to show signs of some improvement.