A U.S. journalist says he is overwhelmed to learn of the efforts that went into securing his release from a Syrian extremist group.


Peter Theo Curtis made his first public remarks Wednesday outside his mother's home in Cambridge, Massachusetts, after being freed three days earlier.


Curtis says he had no idea during his time in captivity that so many ``brave, determined and big-hearted people'' were working for his release. He says he is also grateful for the many people who have welcomed him back since his return.


The 45-year-old writer was released by al-Nusra Front, a Sunni extremist group.


Curtis returned to the United States on Tuesday and was reunited with his family.