The Geneva-based UN health agency said the possible consequences of a further international spread of the outbreak, which has killed almost 1,000 people in four West African countries, were "particularly serious" in view of the virulence of the virus.
The WHO called for a coordinated international response to stop and reverse the epidemic’s international spread in a statement after a two-day meeting of its emergency committee on Ebola.
The agency said that all states with Ebola transmission should declare a national emergency, as some of the stricken countries already have done.
The current outbreak was the most severe in the almost 40 years since Ebola was first identified in humans, the body said, adding that it was partly because of weaknesses in the countries currently affected, where health systems were fragile and lacking in human, financial and material resources.
Although most cases of Ebola are in the remote area where Guinea borders Sierra Leone and Liberia, alarm over the spread of the disease increased last month when a US citizen died in Nigeria after traveling there by plane from Liberia.
After an experimental drug was administered to two US charity workers who were infected in Liberia, Ebola specialists have urged the WHO to offer such drugs to Africans. The UN agency has asked medical ethics experts to explore this option next week.
