"The safety and security of US citizens is our paramount concern," deputy spokesperson Marie Harf said, confirming the State Department was facilitating the medical evacuation with the Centres for Disease Control and Prevention (CDC).
"Every precaution is being taken to move the patients safely and securely, to provide critical care en route on a non-commercial aircraft and to maintain strict isolation upon arrival in the United States."
They will be "taken to medical facilities with appropriate isolation and treatment capabilities," Harf added in her statement.
Samaritan's Purse, a US charity, has said that two of its staff members, doctor Kent Brantly and another American missionary worker, Nancy Writebol, were stricken with the virus in Liberia.
Both "are in stable but grave condition," the group said on Thursday in a statement.
Harf declined to identify the two patients who would be evacuated due to privacy concerns.
Emory University Hospital, in southern Georgia, has also said that it is preparing to receive "a patient with Ebola virus infection to its special facility containment unit within the next several days."
But it was not immediately clear if either Brantly or Writebol would be taken to Emory.
"CDC protocols and equipment are used for these kinds of medical evacuations so that they are carried out safely," Harf added.
This was done in an effort to protect "the patient and the American public, as has been done with similar medical evacuations in the past," she added.
Brantly, 33, became infected with Ebola while working with patients in the Liberian capital of Monrovia as he helped treat victims of the worst Ebola outbreak in history.
The World Health Organization warned West Africa's Ebola-hit nations that the epidemic was spiralling out of control and could spread to other countries.
The WHO raised the death toll by 57 to 729 on Thursday, announcing that 122 new cases had been detected between Thursday and Sunday last week, bringing the total to more than 1 300 since the epidemic began earlier this year.