President Barack Obama has said the United States cannot be seen as shying away from the battle against Ebola.
Mr Obama did not directly criticise quarantine policies for returning healthcare workers implemented in the states of New York and New Jersey, but he said the response to Ebola needs to be sensible and "based on science", while supporting healthcare workers going overseas to fight the disease.
Mr Obama said healthcare workers who go to Africa should be "applauded, thanked and supported".
He said a robust response in Africa will stop the spread of the disease in the US.
"We don't want to discourage our healthcare workers from going to the front lines and dealing with this in an effective way," he said.
He reminded Americans only two people have contracted the disease in the US and both are now disease-free.
The president spoke to reporters from the White House after a phone call with one of those patients, nurse Amber Vinson, just after her release from hospital.
He also called a USAID team deployed to West Africa and said he plans to meet with public health workers on Wednesday who have been there or are planning to go, to talk about how public policy "can support the incredible heroism that they are showing".
"America cannot look like it is shying away because other people are watching what we do," Mr Obama said.
"If we don't have a robust international response in West Africa, then we are actually endangering ourselves here back home. In order to do that, we've got to make sure that those workers who are willing and able and dedicated to go over there in a really tough job, that they're applauded, thanked and supported.
"That should be our priority. And we can make sure that when they come back they are being monitored in a prudent fashion."
State policies, some of which directly contradict Mr Obama's recommendations, have sown confusion about what is needed to stop Ebola from spreading in the United States.
While public health advocates denounce state quarantines as draconian and scientifically baseless, anxious citizens in non-quarantine states are asking whether they are at greater risk because their governors and the president have adopted a lesser level of caution.
For the first time on Monday, the Centres for Disease Control recommended 21 days of isolation and travel restrictions for people at highest risk for Ebola - a nurse stuck by a needle while treating an Ebola patient in Guinea, for example - even if they have no symptoms. States are still free to go above and beyond the CDC guidelines.
Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Disease at the National Institutes of Health, defended the Washington policy, but said that states have a right "to go the extra mile" if they wish.
Dr Fauci declined to criticise the more stringent quarantine policies implemented in New York and New Jersey, saying: "'They're doing it in good faith."