Just weeks after a dramatic purge of China's top general, the CIA is moving to capitalize on any resulting discord with a new public video targeting potential informants in the Chinese military.

The US spy agency on Thursday rolled out the video depicting a disillusioned mid-level Chinese military officer, in the latest US step in a campaign to ramp up human intelligence gathering on Washington's strategic rival.

It follows a similar effort last May that focused on fictional figures within China's ruling Communist Party that provided detailed Chinese-language instructions on how to securely contact US intelligence.

CIA Director John Ratcliffe said in a statement that the agency's videos had reached many Chinese citizens and that it would continue offering Chinese government officials an "opportunity to work toward a brighter future together."

Last month, China's defense ministry announced that Zhang Youxia, second-in-command under Xi as vice-chairman of the Central Military Commission (CMC), was under investigation, the highest-profile removal of a senior Chinese military leader in decades.

The short CIA video posted to its YouTube channel appeared aimed at exploiting domestic political fallout from Beijing's years-long crackdown on military corruption that has hit the upper echelons of the People's Liberation Army (PLA) beyond Zhang.

"Anyone with leadership qualities is bound to be subject to suspicion and ruthlessly eliminated," the fictional officer in the video says in Mandarin. "Their power is built on countless lies," he says, referring to superiors.

The CIA has said it is confident that the online campaign is penetrating China's "Great Firewall" internet restrictions and reaching the intended audience.

"Our past videos reached millions of people and inspired new sources," a CIA official told Reuters on condition of anonymity, without providing details.

The CIA has been investing heavily into countering China and has tried to rebuild its spy network in the country after Beijing crippled its reach by killing or imprisoning numerous US sources between 2010-2012, according to reports.

American officials say China's spy agencies have worked tirelessly to recruit current and former US employees, and in recent years Beijing has published accounts of what it says are US spy rings it has uncovered in China.

The high-stakes spy games are part of an escalating military and technological rivalry that many observers deem to be a new form of cold war.