U.S. President Barack Obama has confirmed the death of Kayla Jean Mueller, a 26-year-old American woman who was being held hostage in Syria by the Islamic State (IS) militant group.
In a February 10 statement, Obama vowed that "No matter how long it takes, the United States will find and bring to justice the terrorists who are responsible for Kayla's captivity and death."
Mueller's parents also released a statement saying they had been informed of their daughter's death.
The White House said Mueller's family received a private message from IS on February 8 or 9 with "additional information" leading to the conclusion Kayla Mueller was dead.
The militant group said on February 6 that Mueller had been killed in an air strike by Jordanian warplanes.
Mueller was the last known American being held by IS.
Two other U.S. nationals, both journalists, James Foley and Steven Sotloff, were beheaded by IS last year.