The U.S. military campaign to help eradicate Ebola from West Africa sounds anything but surgical. It will take–for now–nearly 4,000 American troops, cost $750 million, and it could last a year or longer.

"This is not a small effort, and this is not a short period of time," the commander of U.S. forces in Africa, General David Rodriguez, said on Tuesday.

Briefing reporters at the Pentagon, Rodriguez offered new details about the military mission that will be based in Liberia, which is part of what the Obama administration has called a "whole of government" effort to halt the Ebola outbreak before it hits the U.S. in earnest.

Troops are helping to construct seven testing labs and 17 treatment facilities, which they hope to have up and running by mid-November, Rodriguez said.

He emphasized that a core goal is to protect U.S. soldiers from becoming infected themselves and noted that a vast majority of them will not come in direct contact with Ebola patients.

But a few dozen troops trained for the most dangerous nuclear, biological, and chemical environments will be tasked with staffing the testing centers.

"The bottom line is it’s the highest level" of training, Rodriguez said. "They are specifically trained to do that, and that is their speciality."

U.S. troops survey a construction site outside Monrovia in Liberia (James Giahyue/Reuters)

U.S. and international health officials have sounded increasingly urgent warnings about the outbreak in West Africa, which has killed more than 3,400 people and infected 7,500 in Liberia, Guinea and Sierra Leone, according to the World Health Organization.

Ebola hit the U.S. mainland last week with the diagnosis of Thomas Eric Duncan, who had traveled to Dallas from Liberia. Duncan is in critical condition and receiving an experimental drug, hospital officials said. A nurse in Spain on Monday became the first person to contract the disease outside of Africa.

President Obama's critics on the right have noted that the U.S.'s deployment of 4,000 troops to Africa, including "boots on the ground," is more than the announced number of additional military advisers sent to Iraq to fight the Islamic State.

Rodriguez said the goal of building the new facilities is to get 70 percent of infected Ebola patients into treatment centers. Health officials believe at that point, the epidemic "curve" will bend and the outbreak can be stopped.

U.S. troops will be on the ground in Africa for at least a year, he posited.

"We’re going to take as long as we’re needed, but not longer than we’re needed," Rodriguez said.

Will the 4,000 soldiers be enough?

"I don’t foresee more than that right now, but things can change," he replied.

Reporters also pressed the general on whether U.S. troops would be safe not only from the disease, but from the local population. There have been isolated incidents of violence from villagers mistrustful of quarantines and suspicious of health workers, including one shocking attack that left eight members of a delegation of government officials and journalists dead in Guinea last month.

Rodriguez said there have been no problems thus far, and he reminded reporters that Ebola is physically debilitating.

"When these people get infected, they are not capability of doing a mounted attack or anything," he said.