The US is planning measures to screen incoming air passengers for Ebola, President Barack Obama has said.
The likelihood of an Ebola outbreak in the US is “extremely low”, Mr Obama said, but “we don’t have a lot of margin of error”.
More than 3,400 people have died in West Africa in the world’s deadliest outbreak of the viral disease.
Mr Obama’s comments came six days after a Liberian man became the first case of Ebola diagnosed on American soil.
Some 3,400 people have died in the outbreak – mostly in West Africa.
Barack Obama also criticised foreign governments for not acting “as aggressively as they need to” against the outbreak.
“Countries that think that they can sit on the sidelines and just let the United States do it, that will result in a less effective response, a less speedy response, and that means that people die.
“And it also means that the potential spread of the disease beyond these areas in West Africa becomes more imminent,” Mr Obama said.