A Georgia man who wrote that he was "ready for Jihad" before booking a flight overseas to join the Islamic State group has been sentenced to 15 years in federal prison.

Despite menacing social media postings read by prosecutors in court Tuesday, 38-year-old Leon Nathan Davis III of Augusta sobbed as he told the judge: "I love my country and I am an American."

Davis pleaded guilty in May to charges that he sought to join a known terrorist group. His attorney told the judge Davis converted to Islam a decade ago while in prison for cocaine trafficking. Davis says he was later "brainwashed" by propaganda of radical Muslims.

Prosecutors say Davis wrote online that he wanted "to kill Zionists and bring down Israel and the United States of America."