FREETOWN, Sierra Leone (CNN) -- Guinea has closed its border with Sierra Leone to suppress the spread of the deadly Ebola virus, a Sierra Leone border police official told CNN.
The virulent virus continues to advance from its epicenter in Sierra Leone to neighboring Guinea, Liberia and Nigeria. Other West African governments are attempting to contain the outbreak, which has been declared a "public health emergency of international concern" by the World Health Organization.
The United States and the United Kingdom welcomed the efforts of the World Health Organization to halt the spread of Ebola and on Saturday vowed to increase assistance to help combat the disease in West Africa.
Meanwhile, the Zambian government banned arrivals of people from countries where there has been an Ebola outbreak, as a preventative measure to stop the virus from entering the country.
"All delegates from any of the countries affected by Ebola Virus disease are restricted from entering Zambia until further notice," said Dr. Joseph Kasonde, Zambia's Minister of Health in a statement on Saturday.
Since the onset earlier this year, the virus is believed to have infected 1,779 people, killing 961 according to the latest figures released by WHO.
Nigeria and Liberia have both declared a state of national emergency this week, in an effort to control the unprecedented epidemic.
The U.N. health agency described it as the worst outbreak in the four-decade history of tracking the disease.
™ & © 2014 Cable News Network, Inc., a Time Warner Company. All rights reserved.