HONOLULU, HAWAII (REUTERS) - Ikaika Erik Kang, a 34-year-old US Army sergeant stationed in Hawaii, who prosecutors say is pictured here with the Islamic State in Iraq and Syria (ISIS) flag, will appear in court on Monday (July 24) in Honolulu.

Kang, who was arrested on July 8, is accused of trying to provide classified military documents, a small drone and training in firearms to undercover FBI agents he believed were affiliated with ISIS, according to court documents.

The FBI said Kang swore allegiance to the ISIS leader, but Kang's attorney Birney Bervar argues that the Army failed to address his client's mental problems after he returned from deployments to Iraq in 2011 and Afghanistan in 2014.

And Mr Bervar says the FBI targeted him in the sting operation. "They've exploited his mental illness and has thrown gasoline on the fire on his mental illness to get him to commit a crime that they can arrest him for," he said.

If convicted, Kang could face a maximum sentence of 20 years in prison on each criminal count, according to the Department of Justice.