China will send an elite military unit to Liberia to help stop the spread of the deadly Ebola virus, the country's foreign ministry says.

The announcement comes after the United Nations called for a greater global effort to fight the disease, which has killed nearly 5,000 people in Liberia, Sierra Leone and Guinea.

Washington has led the international drive against Ebola, sending thousands of troops and committing about $1 billion, but Beijing has faced criticism for not doing enough.

Lin Songtian, the ministry's director general of African affairs, said a squad from the People's Liberation Army (PLA) will build a 100-bed treatment centre in Liberia, the first such facility to be constructed in West Africa and run by a foreign country.

The centre will be open for operation in a month's time, he told a briefing in Beijing. China will also dispatch for the first time 480 PLA medical staff to treat Ebola patients, he said.

"China's assistance will not stop until the Ebola epidemic is eradicated in West Africa."

Several thousand Chinese nationals live in Guinea, Liberia and Sierra Leone, and about a million Chinese nationals live on the African continent, he said.

China is Africa's biggest trade partner, tapping the continent's rich vein of resources to fuel its own economic growth over the past couple of decades.

The country has so far donated $123 million to 13 African countries and international organisations to combat Ebola, according to the Chinese government.

It has also dispatched hundreds of aid workers to Africa to combat Ebola, including health experts and medical staff.

Chinese drug maker Sihuan Pharmaceutical Holdings Group has sent several thousand doses of an experimental Ebola drug to Africa and is planning clinical trials there.

Foreign efforts to help combat Ebola have been complicated by domestic public health policy issues.

Some US states have slapped mandatory quarantines on health workers returning from Ebola-hit states, while Australia this week imposed a blanket ban on visas from the three affected states.

Health experts have decried the measures as draconian, and say such policies may discourage badly needed foreign doctors and nurses from volunteering to help.

Medical professionals say Ebola is difficult to catch and is spread through direct contact with bodily fluids from an infected person and is not transmitted by asymptomatic people.

Reuters