A 42-year-old man from a small New York town on the edge of Lake Erie on Wednesday became the latest American charged with alleged support for extremists in Iraq and Syria, officials said.
Prosecutors say that Arafat Nagi from Lackawanna pledged allegiance to the Islamic State (IS) group in Iraq and Syria, and its leader Abu Bakr al Bagdadi.
He travelled to Turkey in 2012 and 2014, intending to meet members of the group, buying quantities of military apparel and combat kit prior to flying, officials said.
Among items he purchased were body armor, a hunting knife, machete and night vision goggles, prosecutors said.
It was not clear whether he ever met IS personnel in person.
An informant told the FBI he talked and argued about violent jihad in the community, and blamed the United States for the killing of rebels in Yemen.
Nagi faces up to 15 years in prison and a fine of $250,000 if convicted, prosecutors said.
The head of the FBI, James Comey, this month told the Senate select committee on intelligence that upwards of 200 Americans have traveled or attempted to travel to Syria to join up with IS.
Radicalization of impressionable Americans by IS propaganda online has raised fears about the threat of lone wolf attacks in the United States, and arrests of suspects have become common.
In Georgia, a 37-year-old man was sentenced to 15 years in jail on Tuesday after he pled guilty in May to attempting to provide material support to IS.
"This defendant planned for over a year to join, assist and fight alongside an enemy of the United States," said US Attorney Edward Tarver of the southern district of Georgia.
Davis was arrested at the Atlanta Hartfield-Jackson Airport in October 2014 on a parole violation, after buying a ticket to fly to Turkey, a key transit point for travel into Syria.
In Florida, the FBI also announced on Tuesday that a self-professed IS supporter was also charged with attempting to set off a backpack bomb.
Harlem Suarez, 23, from Key West drew authorities' attention because of his extremist Facebook posts. He allegedly paid a cooperator to construct a telephone-controlled bomb.
The complaint said Suarez intended to bury the bomb on the beach and detonate it. Suarez had also placed an online order for an AK-47 rifle, the FBI said.
Suarez allegedly said he attempted to contact IS in Syria but never got a response, according to the complaint.
Also Tuesday, the FBI said another Islamic State supporter was sentenced to 10 years in jail for illegally possessing a firearm.