But it could cause damage to innocent nations, Snowden claims.
The US National Security Agency (NSA) working on a new cyber defence system, capable of automatically launching counter-strikes against cyberattacks from foreign countries, without any of its personnel overseeing it.
This is the latest claim by whistleblower Edward Snowden. Featuring algorithms that can automatically scan huge portions of metadata to pick out malicious traffic, the agency's MonsterMind project could neutralise the threat and even launch a retaliatory strike.
Snowden cautioned that the project would cause damage to innocent nations as it could camouflage the origin of the attacks by redirecting them via PCs in other countries.
In an interview with WIRED magazine, Snowden said: "You could have someone sitting in China, for example, making it appear that one of these attacks is originating in Russia. And then we end up shooting back at a Russian hospital. What happens next?"
Snowden noted that while other cyber warfare programmes also automatically identify and block hacker attacks, the one under development by the NSA would be a greater threat to privacy as it requires to access almost all private communications entering the US from overseas in order to work.
Snowden added: "If we're analysing all traffic flows, that means we have to be intercepting all traffic flows.
"That means violating the Fourth Amendment, seizing private communications without a warrant, without probable cause or even a suspicion of wrongdoing. For everyone, all the time."
However, Snowden agreed to return to the US even if it meant time in prison.
Snowden added: "I told the government I'd volunteer for prison, as long as it served the right purpose.
"I care more about the country than what happens to me. But we can't allow the law to become a political weapon or agree to scare people away from standing up for their rights, no matter how good the deal."