The United Nations unveiled plans on Thursday for a special mission to combat the worst Ebola epidemic on record in West Africa, as the death toll hit 2,630 and France became the latest Western nation to step up its support.

French President Francois Hollande announced the deployment of a military hospital to remote Forest Region of southeastern Guinea, where the outbreak was first detected in March.

Since then the virus has infected at least 5,357 people, according to World Health Organization (WHO), mostly in Guinea, neighboring Sierra Leone and Liberia. It has also spread to Senegal and Nigeria.

With fragile West African healthcare systems overrun by the outbreak, Hollande said France's response would not be limited to contributing to 150 million euros ($194 million) in aid promised by European Union nations.

"We must save lives," he told a news conference. "I have asked the defense minister to coordinate this action and to include military doctors and the civil protection agency plus air support."

U.S. President Barack Obama, calling the disease a threat to global security, promised this week the deployment of 3,000 U.S. troops to help contain the epidemic. Britain also announced on Wednesday it would help to provide a further 700 treatment beds in Sierra Leone, its former colony.

One of the most deadly diseases, there is no known cure for the hemorrhagic fever, though development of several treatments and vaccines is being fast-tracked.

In New York, the 15-member U.N. Security Council was due to adopt a resolution later on Thursday that declares the outbreak of Ebola, spread by contact with the body fluids of infected people, a "threat to international peace and security".

In a letter circulated to the Council, U.N. Secretary-General Ban Ki-moon said he will appoint a special envoy to head the U.N. Mission for Ebola Emergency Response (UNMEER), based in the region.

"The strategic priorities of the mission will be to stop the spread of the disease, treat the infected, ensure essential services, preserve stability and prevent the spread to countries currently unaffected," Ban wrote.

ATTACK ON JOURNALISTS, OFFICIALS

The WHO warned on Thursday there were no signs yet of the outbreak slowing, particularly in the three countries hardest hit. It said a surge in Liberia was being driven by an increase in the number of cases in the capital, Monrovia, where 1,210 bed spaces were urgently needed - five times the current capacity.

A U.S. C-17 military aircraft landed in Monrovia international airport on Thursday with a team of engineers to assess the capacity of the runway to handle large planes.

The United States plan will include the construction in Liberia - the country hit hardest by the outbreak - of 17 Ebola treatment centers with 100 beds each, plus training thousands of healthcare workers.

French forces will be based in an area where authorities are battling fears and stigma about the highly contagious disease.

Nine Guineans, including two journalists and several officials trying to educate the local population on the risks of Ebola, were missing on Thursday after being attacked by stone-throwing residents in Wome, a village close to the town of Nzerekore.

Damantang Camara, a spokesman for Guinea's government, said he could not confirm a local media report of six dead as officials had not seen any bodies. "A team has been dispatched to verify more information," he said.

In a rare piece of good news, the latest data showed no new deaths in Sierra Leone in the one day since the previous update.

The government in Sierra Leone has locked down the country, limiting movements for three days from midnight on Thursday. It said extreme measures are needed to contain the outbreak.

However, many people fear the decision will bring more hardship to a nation that is already one of the poorest on earth and critics also question whether it will even be effective.

(Additional reporting by Umaru Fofana in Freetown; Kate Kelland in London, Tom Miles in Geneva, John Irish in Paris and Daniel Flynn in Dakar; Writing by Bate Felix; Editing by Daniel Flynn and David Stamp)