A New York man facing terrorism charges for allegedly trying to join ISIS or another extremist group in Syria was ordered held without bail after a brief court hearing Monday. 

Elvis Redzepagic, 26, was charged Saturday in Brooklyn with attempting to provide material support to a foreign terrorist organization; federal authorities said he was prepared to strap on a bomb and sacrifice himself for jihad.

Police on Long Island arrested Redzepagic on Feb. 2 on a minor, unrelated drug charge, and he told them: "I'm going to leave this country, and I'm going to come back with an Army - Islam is coming," according to a federal court complaint.

A defense attorney told the judge at Monday's hearing that her client's medical and mental health needs should be evaluated. Lawyer Mildred Whalen previously said Redzepagic has cooperated with law enforcement.

"We will be working with his family in the hope that the court and the government will see that what he needs is counseling and support, not imprisonment," she said in an email.

Prosecutors argued for no bail, saying Redzepagic is a danger to the community and citing two 911 calls from the Commack home where he lived with his parents. In one instance, investigators said Redzepagic threatened to behead his mother and began to cut tattoos off his own body with a knife.

He allegedly told one of the responding officers, "I feel like stabbing you right now."

In a previous police response to the home, Redzepagic allegedly told police that he was "going to leave this country and going to come back with an Army -- Islam is coming." 

Shaken neighbors say they had no idea Redezpagic was following what prosecutors call a violent ideology.

"It's very scary to know it's homegrown here, right in the Commack area," said one neighbor. "I never expected this." 

Another neighbor, Andrew Ross, recalled seeing cops taking Redezpagic from his home.

"The final shock was when the guy was screaming last week and they took him out in handcuffs," he said. "It's just a pathetic situation in this kind of neighborhood. See how quiet it is? It's this quiet all the time." 

Authorities have prosecuted a number of people accused of trying to join the Islamic State group and other militants in recent years, though in some cases, the accused haven't actually succeeded in traveling overseas.

Redzepagic "was persistent in his efforts" to join Islamic militants in civil-war-ravaged Syria, making it to Turkey in 2015 and Jordan last year and even getting to the Syrian border, said William F. Sweeney, assistant director in charge of the FBI's New York field office.

Redzepagic told authorities after his arrest that he'd become a devout Muslim while in Montenegro, in the Balkans, and believed a cousin was a battalion commander in Syria for the Islamic State or the group once known as the Nusra Front, according to the court complaint. The latter group - now called the Fatah al-Sham Front, and also known at times as Jabhat al-Nusra - is an al-Qaida affiliate.

No one immediately responded to phone or email messages to Redzepagic's relatives.

After telling his cousin he wanted to join him, Redzepagic went to Turkey in July 2015 and aimed for Syria. He got cab rides to the border, then directions to a border wall manned by the military, followed by instructions to try to cross instead by making a two-day trip through the woods, the complaint says.

He'd been willing to put on a bomb and sacrifice himself, he told authorities after his arrest, though he told them at another point he just wanted to "feed the children" in Syria. But frustrated that he didn't getting more help crossing the border, Redzepagic returned to the U.S., the complaint says.

"Since I got back from Turkey from trying to perform jihad and join Jabhat al-Nusra the CIA has been bothering me," he wrote to a Facebook contact in October 2015, the complaint says. "It's annoying but I out smarted them."

The CIA declined to comment Saturday on the case.

He also told various Facebook contacts that "I just don't like this country," apparently meaning the U.S., and that "jihad is the best for u," according to the complaint.

"There will come a time where people will only know to say Allahu akbar," he wrote in one message, using the Arabic phrase for "God is great," says the complaint.

Redzepagic went to Jordan last August to try again to get to Syria, but Jordanian officials stopped him and asked why he wanted to go there. He said he wanted to study Arabic, the complaint says.

It says he then told the same to U.S. Customs and Border Protection officials, who found he had electronic files about jihad. He said he'd downloaded them two years earlier, the complaint adds.

It's not immediately clear whether he remained on federal authorities' radar between then and his arrest in February. Long Island police notified federal authorities about the arrest, and although he was released without bail on the minor charge, he willingly continued talking to federal agents and let them scrutinize his phone, laptop and Facebook account, the complaint says.