A 50-year-old Chinese man has pleaded guilty to being involved in a plot to hack into systems containing sensitive US military data.
Su Bin is believed to have been part of a group targeting data relating to fighter jets, cargo aircraft and weapons.
The US Department of Justice (DoJ) said in a statement that Mr Su sought "commercial gain" from his actions.
Mr Su, a Chinese resident, was arrested while working in Canada in 2014. He faces five years in prison and a $250,000 (£170,000) fine.
The DoJ stopped short of saying the Chinese government was involved in buying the secrets from Mr Su and his co-conspirators.
However, theft of sensitive data is a general accusation the US has frequently levelled at China in the past.
"Su Bin admitted to playing an important role in a conspiracy, originating in China, to illegally access sensitive military data, including data relating to military aircraft that are indispensable in keeping our military personnel safe," said the US Assistant Attorney General for national security, John Carlin.
He added: "This plea sends a strong message that stealing from the United States and our companies has a significant cost; we can and will find these criminals and bring them to justice."
Mr Su Bin admitted to working with two people in China from October 2008 to March 2014 to gain unauthorised access to protected computer networks in the US. California-based systems belonging to military contractor Boeing were among them.
Once information was stolen, the DoJ said it was illegally exported to China.
Due to his grasp of English, Mr Su appeared to act as a form of middle man, advising co-conspirators in China who and what to target. He also translated the English data into Chinese for the "final beneficiaries" of the stolen information.
Mr Su reportedly ran a Chinese aviation technology company with an office in Canada. He was arrested while trying to gain Canadian citizenship.
Following the plea, Mr Su's lawyer said: "In resolving this matter Su Bin hopes to move on with his life."