Three New York City residents pleaded not guilty on Friday to U.S. charges that they attempted to provide support to Islamic State militants.
The men entered their pleas during a hearing in Brooklyn following their arrest last month and indictment on Monday over a plot by two of them to travel to Syria to fight on behalf of the radical group.
Akhror Saidakhmetov, 24, Abdurasul Hasanovich Juraboev, 19, and Abror Habibov, 30, appeared in court in blue jail garb and shackles.
U.S. District Judge William Kuntz set a hearing for June 19 as prosecutors prepare to turn over recordings and classified evidence gathered to date.
Adam Perlmutter, a lawyer for Saidakhmetov, told reporters after the hearing his client was "obviously very concerned, very frightened by what's happening to him."
"Obviously he thinks he did nothing wrong," he added.
A U.S.-led coalition has been fighting Islamic State, which controls broad swaths of Iraq and Syria. FBI Director James Comey last month said that law enforcement had Islamic State-related investigations into homegrown extremists in all 50 states.
Authorities arrested Saidakhmetov, a Kazakhstan citizen, on Feb. 24 at John F. Kennedy International Airport in New York, where prosecutors said he was attempting to board a flight to Turkey on his way to Syria.
Prosecutors said Juraboev, a Uzbekistan citizen, had previously also bought a ticket for a March flight to Istanbul. Prosecutors also charged Habibov, another Uzbekistan national, who authorities say helped fund Saidakhmetov's efforts.
Prosecutors said Juraboev came to authorities' attention in August after posting messages on an Uzbek-language website stating his desire to join Islamic State and his willingness to kill U.S. President Barack Obama.
Agents interviewed Juraboev in August, when he acknowledged wanting to fight for Islamic State in Syria and told them about a friend, Saidakhmetov, who shared similar views, prosecutors said.
Initially charged through a criminal complaint, the men were indicted by a grand jury Monday for attempting and conspiring to provide material support to Islamic State.
Juraboev and Saidakhmetov also face a charge of conspiring to use a firearm, while Saidakhmetov faces a fourth charge of travel document fraud in connection with his attempted trip. All three men are being held without bail before trial.