New concern worldwide after 1st Ebola infection outside Africa

The troops will help operate the seven mobile labs, where they could be working with the blood of infected patients, Army Gen. David Rodriguez told reporters.

The labs will receive up to 100 samples per day from local clinics and will be able to give a diagnosis in hours, instead of several days, the general said.

Rodriguez, who leads the US Africa Command, said military members who help diagnose patients will be adequately protected from the disease.

"I am confident that we can ensure our service members' safety and the safety of their families and the American people," he said.

Military personnel who work in the laboratories are trained at a very high level, Rodriguez said, adding that US military efforts to deal with the Ebola crisis are expected to cost 750 million US dollars in six months.

According to Pentagon officials, as many as 4,000 US servicemen will be deployed in West Africa. The White House said it was the largest-ever US response to an international health crisis.

Most of the troops will work on constructing treatment centers, training local health care providers and helping with the logistics of the global efforts.

So far, 350 US military personnel are on the ground in West Africa among international aid groups to contain the spread of the virus. The disease has killed 3,974 people and could infect as many as 1.4 million, according to the US Centers for Disease Control and Prevention.