Aid missions are being readied by Western militaries to help Africa's Ebola-hit nations.
The epidemic which has sparked killings in panicked southern Guinea and forced a nationwide shutdown in Sierra Leone.
The United States said a 3,000-strong contingent of troops due to deploy to Liberia would help train health workers, while Germany and France unveiled plans to send military transport planes to help contain the spread.
The announcements came after Sierra Leone launched a nationwide three-day shutdown to contain the deadly spread of an Ebola epidemic described by the UN Security Council as a threat to world peace.
The outbreak has killed more than 2,600 people in Guinea, Liberia and Sierra Leone this year, cutting a swathe through entire villages at the epicentre and prompting warnings over possible economic catastrophe from the World Bank.
Most of Sierra Leone's six million people were confined to their homes from midnight (0000 GMT) on Friday, with only essential workers such as health professionals and security forces exempt.
"These are extraordinary times and extraordinary times require extraordinary measures," said Sierra Leone President Ernest Koroma, launching the campaign with a televised address to the nation.
Almost 30,000 volunteers began door-to-door rounds to educate locals and hand out soap, in an exercise expected to lead to scores more patients and bodies being discovered in homes.
United States Rear Admiral John Kirby told reporters the first US military cargo plane arrived in neighbouring Liberia on Thursday as part of the effort to help fight the epidemic.
"Right now, the effort does not include US military personnel treating Ebola patients," Kirby said. "We're going to be in support of other health care workers that are experts at doing this."
Kirby said a C-17 aircraft with equipment and seven service members landed on Thursday, with two more cargo planes expected this weekend carrying 45 personnel.
- Exponential spread -
The small team will then set up a headquarters for Major General Darryl Williams, who will oversee the US mission to train local health workers and set up additional medical facilities, he added.
The Pentagon has requested up to one billion dollars from Congress for efforts to combat the outbreak, Kirby said.
Obama unveiled the troop deployment to west Africa earlier this week, appealing for urgent global action to prevent the virus from spreading "exponentially".
German Chancellor Angela Merkel announced that Berlin would supply military air transport and a mobile clinic, and could train medical personnel.
Government ministries were still discussing the details of the mission, she said, adding that "it's currently not a question of money, but of capacity and logistics".
A Bundeswehr spokesman told AFP that Germany, in cooperation with France, plans to send up to 100 troops and four Transall C-160 planes to a base in Dakar, or alternatively Bamako, Mali.
"Germany and France have agreed to establish a joint airlift," he said, following a Paris meeting of defence ministers Ursula von der Leyen of Germany and France's Jean-Yves Le Drian.
"The objective is to build a logistics chain from Germany," he said, explaining that the airlift could move about 100 tonnes of medical and aid supplies per week.
Merkel expressed concern at the "dramatic course" Ebola has taken and said bilateral aid was needed because the multilateral organisations cannot contain the rapid spread of the disease on their own.
In Sierra Leone, streets across the capital Freetown, normally a chaotic city of 1.2 million people, emptied from midnight as a 72-hour shutdown began.
"Everyone seems to be complying and this is very good. This is an important way to fight Ebola. We expect everyone to stay at home," Freetown police chief Francis Munu told AFP.
- Rife paranoia -
Shops and offices were shut across the city, and only emergency vehicles plied normally jammed streets.
"Ose to Ose Ebola Tok" -- "House-to-House Ebola Talk" in the widely-spoken Krio language -- will see more than 7,000 volunteer teams of four visiting the country's 1.5 million homes over the coming days.
Paranoia is so rife that in Guinea eight people sent to educate villagers in the south were found dead on Tuesday after coming under attack from locals who apparently feared the delegation meant them harm.
The UN Security Council unanimously adopted a resolution late Thursday declaring that the "unprecedented extent of the Ebola outbreak in Africa constitutes a threat to international peace and security".
Ebola fever can fell its victims within days, causing severe muscle pain, vomiting, diarrhoea and -- in some cases -- unstoppable internal and external bleeding.
More than 550 people have died from the disease in Sierra Leone alone, one of the three hardest-hit nations alongside Guinea and Liberia.