US President Barack Obama will try to "turn the tide" on the Ebola epidemic Tuesday by ordering 3,000 US military personnel to west Africa to curtail its spread as China also dispatched more experts to the region.

The White House said Obama will travel to the Centers for Disease Control and Prevention in Atlanta -- where US Ebola victims were treated -- to make the announcement, meant to spur a global effort to tackle the outbreak that has already killed 2,400 people.

It comes as alarm grows that the worst-ever Ebola epidemic which spread through Liberia, Sierra Leone and Guinea before reaching Nigeria, is out of control. A separate strain of the disease has appeared in the Democratic Republic of Congo.

Most of the US effort, which will draw heavily on its military medical corps, will be concentrated in impoverished Liberia -- the worst hit nation -- with plans to build 17 Ebola treatment centres with 100 beds in each.

China is also sending more medics to neighbouring Sierra Leone to help boost laboratory testing for the virus, raising the total number of Chinese medical experts there to 174, the UN said Tuesday.

The World Health Organization (WHO) said Tuesday it was reconvening its emergency committee in Geneva which declared the outbreak an international health emergency in August, to consider further measures to limit its spread.

Obama will announce that US Africa Command will set up a headquarters in the Sierra Leone capital Monrovia to act as a command and control centre for US military and international relief programmes.

- 500 health workers a week -

But the main element of the push is a six-month training and hygiene drive to tackle the disease head-on.

US advisors will train up to 500 Liberian health care providers per week in how to safely handle and treat victims and their families in a bid to shore up the country's overwhelmed health infrastructure.

The intervention will involve an estimated 3,000 US military personnel, senior officials said, many working at a staging base for transit of equipment and personnel.

Washington will also send 65 experts from the public health service corps to Liberia to manage and staff a previously announced US military hospital to care for health workers who become sick with Ebola.

Ebola prevention kits, including disinfectant and advice, will also be supplied to 400,000 of the most vulnerable families in Liberia.

"What is clear is in order to combat and contain the outbreak at its source, we need to partner and lead an international response," said one senior US official, on condition of anonymity.

China said it is sending a mobile laboratory team to Sierra Leone, where more than 500 people have died so far from Ebola. The 59-person team from the Chinese Centre for Disease Control will include epidemiologists, clinicians and nurses, the WHO said.

"The newly announced team will join 115 Chinese medical staff on the ground in Sierra Leone virtually since the beginning," the agency's chief Margaret Chan said, hailing the new commitment as "a huge boost, morally and operationally".

- 'No threat to US' -

The Obama administration believes its latest emergency action could help "turn the tide" and slow the spread of the epidemic.

The White House however still believes that there is no realistic threat to the United States from Ebola. It believes that any cases that do materialise on the US soil would be quickly isolated.

The US has so far spent $100 million on fighting the epidemic and the US Agency for International Development plans to allocate another $75 million to increase the number of Ebola treatment units and buy protective gear for health providers.

In addition, the administration has asked Congress for a further $88 million. The money is contained in a short term bill to fund the government until mid-December which could pass Congress this week.

More than 100 workers from Centers for Disease Control are already at work in west Africa, and many more staff are coordinating their work at the agency's Atlanta headquarters.

It was unclear how many of the new US personnel would be deployed in direct contact with patients. The number however appears limited.

Obama first said last week that he was going to use a major military deployment to step up US efforts to fight the epidemic.

His remarks, and a recent YouTube message from the president offering guidance to the people of west Africa on halting infections, highlight increasing White House concern about the implications of the rapid spread of the disease.