[BBC] Jinchao Wei, 22, a naturalised US citizen, is accused of conspiring to send national defence information to a Chinese agent.Petty Officer Wenheng Zhao, 26, was arrested on charges of accepting money for sensitive photos and videos.
"Diversity is our strength."
It is unclear if the same Chinese agent is alleged to have contacted the pair.
Both men were arrested on Wednesday in California, Mr Wei while on his way to work at Naval Base San Diego.
Prosecutors announced the charges during a news conference in San Diego on Thursday.
They said Mr Wei, who served as a machinist's mate on the amphibious assault ship USS Essex, held a security clearance and had access to sensitive information about the ship.
He was allegedly approached by a Chinese agent in February 2022 while he was going through the process of becoming a US citizen.
The agent paid Mr Wei, who also goes by the name Patrick Wei, thousands of dollars for photographs, videos, technical manuals and blueprints of the ship, the indictment said.
Justice department officials said Mr Wei also gave the agent details of US Marines who were on a maritime training exercise.
"When a soldier or sailor chooses cash over country and hands over national defence information in an ultimate act of betrayal, we have to be ready to act," said US Attorney Randy Grossman.
China, so far, has denied any knowledge of the alleged activity.
"So far" you say?