A 25-year-old Uzbek resident of New York has pleaded guilty to conspiring to provide material support for the Islamic State militant group in Iraq and Syria, U.S. prosecutors said.
Abdurasul Hasanovich Juraboev posted a message online a year ago offering to kill President Barack Obama or bomb New York's beach resort of Coney Island if ordered to do so by IS.
He now faces up to 15 years in prison.
Juraboev was arrested at home in Brooklyn, New York, in February. He had purchased a plane ticket to Turkey and was due to leave in March to join up with IS, prosecutors said.
"He was prepared to commit a terrorist attack on American soil if he were not able to make that trip," said acting U.S. attorney Kelly Currie.
Juraboev was arrested as part of a swoop on four terror suspects. Charges remain pending against his four co-defendants, all of whom have pleaded not guilty: Akmal Zakirov, Dilkhayot Kasimov and Abror Habibov, all of Uzbekistan, and Kazakhstan native Akhror Saidakhmetov.