Liberian President Ellen Johnson Sirleaf has declared a state of emergency as the country grapples with an outbreak of the deadly Ebola virus.
Speaking on national television she said some civil liberties might have to be suspended.
The Ebola outbreak has also hit Guinea, Sierra Leone and Nigeria, killing more than 930 people.
World Health Organization (WHO) experts are meeting in Geneva, Switzerland, to discuss a response to the outbreak.
The two-day meeting will decide whether to declare a global health emergency.
Ebola, a viral haemorrhagic fever, is one of the deadliest diseases known to humans, with a fatality rate of between 55% and 90%. It is spread through contact with the bodily fluids of Ebola patients showing symptoms.
A WHO statement on Wednesday said 932 patients had died of the disease in West Africa so far, with most of the latest fatalities reported in Liberia, where at least 282 have died of the virus,
Announcing a state of emergency for 90 days, President Sirleaf said in a statement that the government and people of Liberia required "extraordinary measures for the very survival of our state and for the protection of the lives of our people".
She said that "ignorance and poverty, as well as entrenched religious and cultural practices, continue to exacerbate the spread of the disease".
Observers say the Ebola crisis in Liberia has got worse because many people are keeping sick relatives at home instead of taking them to isolation centres.
Amid international concern over the spread of the virus, US President Barack Obama said that the illness "can be controlled and contained very effectively if we use the right protocols.
"The countries affected are the first to admit that what's happened here is the public health systems have been overwhelmed. They weren't able to identify and then isolate cases quickly enough.
"As a consequence, it spread more rapidly than has been typical with the periodic Ebola outbreaks that occurred previously," the president said.
He said that the US was working with Europe and the WHO to provide resources to contain the epidemic.
In other developments:
- Saudi Arabian authorities said that a Saudi man who was treated for Ebola-like symptoms after visiting Sierra Leone has died at a hospital in Jeddah. If confirmed, it would be the first Ebola-related death outside Africa
- Two US aid workers who contracted Ebola in Liberia appear to be improving after receiving an unapproved medicine ahead of their evacuation back to the US
- Concern has also been growing over a number of new cases in Nigeria, the region's most populous nation. On Wednesday, a nurse who treated an Ebola patient became the second person to die of the disease there
Nigeria's Health Minister Onyebuchi Chukwu described the outbreak as a national emergency, adding that "everyone in the world is at risk" because of air travel.
In a surprise move, the WHO said on Wednesday it would convene a meeting of medical ethics specialists next week to decide whether to approve experimental treatment for Ebola.
Some leading infectious disease experts have been calling for experimental treatments to be offered more widely to treat the disease.
The aim of the WHO's emergency committee meeting is to focus solely on how to respond to the Ebola outbreak.
If a public health emergency is declared, it could involve detailed plans to identify, isolate and treat cases, as well as impose travel restrictions on affected areas.
There is no cure or vaccine for Ebola - but patients have a better chance of survival if they receive early treatment.
Ebola has initial flu-like symptoms that can lead to external haemorrhaging from areas like eyes and gums, and internal bleeding which can lead to organ failure.