Pablo Martinez Monsivais/AP

Obama Warns Ebola Outbreak Is 'Spiraling Out of Control'

The president said the disease could infect hundreds of thousands of people if it isn't stopped, but the chances of it hitting the U.S. remain "extremely low."

The Ebola outbreak now has President Obama's full attention.

After drawing criticism for a late and lackluster U.S. response to the disease's spread in Africa, the president on Tuesday used his strongest language to date in warning that the epidemic is "spiraling out of control."

Obama visited the headquarters of the Centers of Disease Control and Prevention in Atlanta to announce a major expansion of the U.S. effort, including the deployment of as many as 3,000 military personnel to west Africa to help confront Ebola.

This is an epidemic that is not just a threat to regional security -- it’s a potential threat to global security if these countries break down, if their economies break down, if people panic."

The president said the scenes out of countries like Liberia are "absolutely gut-wrenching" and that the disease had the potential to infect hundreds of thousands of people if it was not contained.

The reality is this epidemic is going to get worse before it gets better, but right now, the world still has an opportunity to save countless lives. Right now the world has an responsibility to act, to step up, to do more."

In an update on Tuesday, the World Health Organization said nearly 2,500 hundred people had died from the current outbreak, and nearly 5,000 cases had been reported.

Obama's tone about Ebola was markedly different that the one he used as recently as six weeks ago, when he emphasized in response to reporter questions that the outbreak was limited to a few countries that had weak public health systems.

The administration's public alarm has grown steadily since. CDC director Dr. Tom Frieden returned from a trip to the region in late August warning that the outbreak was "worse than I'd feared." Shortly thereafter, Obamafilmed a video in which he spoke directly to west Africans, urging them to heed the directions of authorities and take precautions, particularly when burying loved ones who had died from the disease.

"We have to act fast," the president said Tuesday. "We can't dawdle on this one."

Despite the increased response, Obama said Tuesday the chances of an Ebola outbreak in the U.S. remained "extremely low."

But judging by the urgency in his voice, it is significantly higher than it was just a few weeks ago.