AP

He provided the support to undercover agents Kang believed were part of the Islamic State group.

By at least early 2016, Kang became sympathetic to the group, Mollway said. The FBI began an investigation in August 2016.

Kang provided voluminous, digital documents that had sensitive information including the U.S. military’s weapons file, details about a sensitive mobile airspace management system, various military manuals and documents containing personal information about U.S. service members, prosecutors said.

Trained as an air traffic controller with a secret security clearance, Kang also provided documents including call signs, mission procedures and radio frequencies, prosecutors said.

At one of the meetings with agents Kang believed were part of the Islamic State, he swore loyalty to the group in Arabic and English and kissed an Islamic State flag given to him by a purported Islamic State sheikh, prosecutors said.

He then said he wanted to get his rifle and fight — “just go to downtown Honolulu and Waikiki strip and start shooting,” prosecutors said in a news release in August.

After that, FBI agents arrested him.

In exchange for Kang’s guilty plea, prosecutors said they won’t charge him with additional crimes, including violations of the espionage act, other terrorism-related laws and federal firearms statutes.