Petty Officer Wenheng “Thomas” Zhao, 26, pleaded guilty to conspiracy and receiving a bribe, according to a plea agreement filed in federal court in Los Angeles.

Zhao admitted sending his Chinese handler plans for US military exercises in the Indo-Pacific region, operational orders and electrical diagrams and blueprints for a radar system on a US military base in Okinawa, Japan, according to court documents and US officials. He was arrested in August.

Zhao, who worked at Naval Base Ventura County in California, faces a maximum of 20 years in prison on the charges, but a judge will determine his final sentence.

A lawyer representing Zhao did not immediately respond to a request for comment.

US attorney Martin Estrada of the central district of California said Zhao “betrayed his country and the men and women of the US Navy by accepting bribes from a foreign adversary.”

The US has accused China of an extensive campaign of espionage and cyberattacks, a charge that Beijing has rejected.