Dilkhayot Kasimov, the fourth man charged recently in a terrorism plot to have U.S. residents travel overseas to fight for ISIS, appeared in Brooklyn federal court Thursday in advance of a summer trial.

Kasimov, a 26-year-old Uzbek native dressed in black prison clothes, tugged at a small black beard as Judge William Kuntz II ordered him to return to court on June 16, along with other Central Asians charged in the case.

Prosecutors accuse Kasimov of collaborating with Abror Habibov to raise $1,600 to fund arrangements for a Brooklyn resident, Akhror Saidakhmetov, to travel to Syria to join ISIS. Court papers say that Saidakhmetov had the cash on him on February 25, 2015, when he was arrested at John F. Kennedy International Airport as he was about to catch a flight to Istanbul.

The FBI has warned that these men are among an increasing number of U.S. citizens and residents who have attempted to travel to Syria to join ISIS. Last year more than a dozen Americans were detained as they tried to travel to the Middle East and most were arrested at airports before boarding their flights, according to the FBI.

A major concern for law enforcement globally has been that hundreds of foreign fighters have been returning home from Syria and Iraq with hardened battle skills and the ideological inspiration to unleash domestic terror.

Islamic State and other jihadi groups have also inspired homegrown terror plots in New York. Earlier this month, two Queens women were arrested and accused of conspiring “to prepare an explosive device to be detonated in a terrorist attack in the United States,” according to a federal criminal complaint.

Kasimov did not speak in court Thursday other than to whisper exchanges with his lawyer, Frederick Cohn, and an Uzbek language interpreter. Cohn told the judge he is hiring an investigator to work on the case with him and that he has yet to see the government evidence against his client.

Kasimov pleaded not guilty when he was arraigned last week. In March, Saidakhmetov, Habibov and Abdurasul Hasanovich Juraboev, all young men from the former Soviet republics of Uzbekistan and Kazakhstan, also pleaded not guilty.The government accuses Juraboev of attempting to travel to Syria via Turkey to join ISIS, as well. Court papers also say that Juraboev offered to “engage in act of martyrdom on U.S. soil on behalf of ISIL, such as killing the President of the United States.”

Though Kasimov had an Uzbek interpreter in court, his English is said to be quite good. He and the other men in the case remain at the Metropolitan Detention Center in Brooklyn, as they await their next appearance in June.