HONOLULU -- An active duty soldier based in Hawaii pledged his allegiance to the Islamic State group, helped buy a drone for it to use against American forces and said he wanted to use his rifle to "kill a bunch of people," according to an FBI affidavit.

Ikaika Kang, a sergeant first class in the U.S. Army, made an initial appearance Monday in federal court in Honolulu. He was arrested Saturday on terrorism charges.

Paul Delacourt, the FBI special agent in charge of the Hawaii bureau, said no documents made it to the Islamic State.

Birney Bervar, Kang's appointed attorney, said after Kang's initial court appearance he still doesn't know much about the case. He said he only talked to Kang for a few minutes.

The 26-page affidavit from FBI Special Agent Jimmy Chen lays out details of the yearlong investigation into the 34-year-old soldier, a onetime martial-arts fighter who thought he was dealing with Islamic State agents but was talking to undercover agents or sources instead.

Among the charges was Kang copied secret military documents in 2015 and wanted to provide them to the organization, according to the affidavit.

It also said Kang admitted he voluntarily pledged loyalty to Islamic State leader Abu Bakr al-Baghdadi.

This occurred Saturday at a home in Honolulu, where he thought he was meeting a member of the organization, the affidavit states.

They made combat-training videos he believed would be taken back to the Middle East to help prepare the group's soldiers to fight American forces, according to the affidavit.

Kang, who received extensive combat training, also helped purchase a drone he believed would help Islamic State soldiers escape from American tanks, the affidavit states.

Kang, a trained air-traffic controller based at Hawaii's Wheeler Army Airfield, had his military clearance revoked in 2012 for making pro-Islamic State comments while at work and on-post and threatening to hurt or kill fellow service members.

His clearance was reinstated a year later after he completed military requirements.

However, the affidavit says the Army believed Kang was becoming radicalized in 2016 and asked the FBI to investigate.

Kang has two firearms registered in his name, an AR-15-style assault rifle and a handgun. After the shooting last summer at a gay nightclub in Orlando, Florida, he told an undercover source that the "shooter did what he had to do and later said that America is the only terrorist organization in the world," according to the affidavit.

The document alleges he also later told the same source that "Hitler was right, saying he believed in the mass killing of Jews."

Kang enlisted in the Army in December 2001, just months after the Sept. 11 attacks. He served in Iraq from March 2010 to February 2011 and Afghanistan from July 2013 to April 2014. Kang was assigned to the headquarters of the 25th Combat Aviation Brigade.