Obama said the experts have advised him that it's more effective to let West Africans into the U.S. than it would be to keep them out.
"The problem is that in all the discussions I've had thus far with experts in the field, experts in infectious disease, is that a travel ban is less effective than the measures that we are currently instituting, that involve screening passengers who are coming from West Africa."
Obama said it's important to continue screening West Africans before they get on planes and then after they arrive in the U.S. to see if they're showing signs of disease. Sick people should get medical evaluations, he said. And people who are not sick should list their contact information.
"If we institute a travel ban instead of the protocols that we put in place now, history shows that there is a likelihood of increased avoidance. People do not readily disclose their information. They may engage in something called broken travel, essentially breaking up their trip, so they can hide the fact that they have been to one of these countries where the disease is in place. And as a result, we may end up getting less information about who has the disease. They're less likely to get treated properly, screened properly, quarantined properly. And as a consequence we could end up having more cases rather than less."
Obama said if his medical experts come back to him and recommend additional precautions, "I assure you, we will do it, but it is important in these circumstances for us to look at the history of how these infectious diseases are best dealt with. And it is currently the judgment of all those, involved that a flat-out travel ban is not the best way to go. But we will continue to monitor this. I'm asking these questions.
"If in fact it turns out I'm getting different answers, then I will share them with the American people. We will not hesitate to do what's necessary in order to maximize the chances that we avoid an outbreak here in the United States..."
Obama said he understands that "people are worried" about Ebola. "But what I want to emphasize once again is that right now, we got one individual who came in with the disease. We have two nurses who have been diagnosed with the disease as a consequence of in some fashion being exposed during treatment. And what remains true is that this is not an airborne disease. It has not easy to catch. You can only catch it through being in contact with the bodily fluids of an individual who not only has the disease, but also is showing symptoms of the disease.
"And so it's important, I think, for all of us to keep perspective in terms of how we handle this. We are taking this very seriously at the highest levels, starting with me."
Obama said it's especially important for health care workers to "have more confidence" as flu season arrives, and people with fever come into hospitals across the country. "There may be false alarms and concerns," Obama said.
"And so we're going to spend a lot of time working with our public health workers to make sure that they feel safe and adequately protected. But I want to assure the American people, we're taking this seriously. But this is something that is really hard to catch. And if we do what we need to do, and we stay focused, then this is going to be something that is contained here."
Dozens of U.S. lawmakers, both Republicans and Democrats, have urged President Obama to block travelers from West Africa from entering the United States.
Rep. Dennis Ross (R-Fla.) said Thursday that he is "putting my foot down" and will introduce a bill restricting all commercial flights from traveling to and from Ebola-affected countries until the virus is contained and no longer a threat.
"This legislation is a more serious approach to preventing Ebola from further infiltrating our homeland," Ross said in a statement on his website.
"Airport security screening is a complete smoke and mirror approach to the virus and Americans aren’t buying it. I urge my colleagues to sign onto this legislation and hope Speaker Boehner will quickly call Congress back into session to debate my legislation.”
The Associated Press reported on Thursday that border closings in Ivory Coast, Guinea-Bissau and Senegal have helped halt the spread of Ebola in Africa, confining it to Liberia, Sierra Leone, and Guinea.