Sierra Leone's President Ernest Koroma has ordered the country's entire population to stay in their homes for three days in a bid to stem the spread of the deadly Ebola epidemic.

"All Sierra Leoneans must stay at home for three days," he announced on Saturday, expanding a previous order for a lockdown in the capital Freetown and northern areas of the country nationwide.

"I have made my personal commitment to do whatever it takes to get to zero Ebola infections and I call on every Sierra Leonean in every community to pull together," he added.

People will be ordered to stay home from March 27 to March 29, with "no trading activities across the country".

Authorities in the Muslim-majority state will lift the lockdown for part of the day to allow church services on Palm Sunday.

Guinea, Liberia and Sierra Leone - which have been the centres of the outbreak which has killed more than 10,000 people - have set a goal of cutting off the disease's spread by April 16.

"The economic development of our country and the lives of our people continue to be threatened by the ongoing presence of Ebola in Sierra Leone. The future of our country and the aspirations of our children are at stake," the president said.

One of the deadliest viruses known to man, Ebola is spread only through direct contact with the bodily fluids of the recently deceased or an infected person showing symptoms, such as fever or vomiting.

The worst-ever outbreak of the virus has claimed almost 3700 lives in Sierra Leone, one of three impoverished west African nations that have seen their economies and healthcare systems wrecked by the crisis.