The deadly Ebola virus landed on US soil for the first time on Saturday when a private jet carrying one of two American aid workers infected by the disease touched down in Georgia, television images showed.
A specially fitted jet carrying Kent Brantly, a doctor who was treating Ebola patients in Liberia, arrived at Dobbins Air Reserve Base outside Atlanta, Georgia shortly before 11:50am (1550 GMT) local time, WSB TV reported.
Footage of the arrival filmed from long-distance showed the jet pulling up at an aircraft hangar where it was met by an ambulance and several vehicles.
The convoy then appeared to pull away from the aircraft, headed for an isolation unit at Emory University Hospital in Atlanta.
The ambulance's journey to hospital was also screened live on several networks.
Brantly and Christian missionary worker Nancy Writebol are in serious but stable condition after becoming infected as they helped to battle the worst Ebola outbreak in history which has left more than 700 people dead in west Africa since March.
Both patients are being flown home on a Gulfstream private jet fitted with a collapsible, mobile isolation unit designed to transfer employees from the US Centers for Disease Control and Prevention (CDC) exposed to contagious diseases.
Brantly and Writebol are to be treated at Emory's state-of-the-art isolation unit, which has previously treated an individual infected during the SARS epidemic in 2003.
It is one of only four facilities in the United States and is located near the CDC headquarters in Atlanta.
"It is physically separate from other patient areas and has unique equipment and infrastructure that provide an extraordinarily high level of clinical isolation," Emory Healthcare said in a statement.
It the first time a patient infected with Ebola has been treated anywhere in the United States.
The arrival of the first case has triggered anxiety in some quarters, with television personality Donald Trump arguing that the patients should be barred from returning to American soil.
But Bruce Ribner, who oversees the isolation unit at Emory, dismissed the criticism of the decision to airlift the aid workers.
"They have gone over on a humanitarian mission [and] they have become infected giving medical care," said Ribner.
"We owe them the right to receive the best medical care that is available."
The US State Department said the "safety and security of US citizens" remained the paramount concern.
"Every precaution is being taken to move the patients safely and securely, to provide critical care en route on a noncommercial aircraft, and to maintain strict isolation upon arrival," State Department deputy spokeswoman Marie Harf said.
The latest outbreak of Ebola in west Africa has killed 729 people of the more than 1,300 infected since March.
The World Health Organization has said the fast-moving outbreak was causing "catastrophic" loss of life in the affected countries of Guinea, Liberia, Nigeria and Sierra Leone.
Ebola, which has no vaccine, causes severe muscular pain, fever, headaches and, in the worst cases, unstoppable bleeding.
It has killed around two-thirds of those it has infected since its emergence in 1976, with two outbreaks registering fatality rates approaching 90%.