US President Barack Obama said in an interview aired Wednesday that some, but not necessarily all, cyber attacks on US firms and infrastructure originating in China were "state sponsored."

In an interview with ABC News, Obama also cautioned about the need to avoid "war rhetoric" when discussing cyber attacks, and called on Congress to act to strengthen cyber security while protecting civil liberties.

Obama was asked about claims in Congress that recent cyber strikes on US firms amounted to the United States being at "war" with China.

"You know, there's a big difference between them engaging in cyber espionage or cyber attacks and obviously a hot war," Obama said in the interview recorded Tuesday.

"What is absolutely true is that we have seen a steady ramping up of cyber security threats. Some are state sponsored. Some are just sponsored by criminals."

"We've made it very clear to China and some other state actors that, you know, we expect them to follow international norms and abide by international rules.

"And we'll have some pretty tough talk with them. We already have," Obama said, complaining that billions of dollars and industrial secrets were lost to the consequences of cyber hacking.

China earlier Wednesday said that it was willing to cooperate with the United States and others to combat hacking and also said it was a victim of such attacks.

"What is necessary in cyberspace is not war, but rather regulation and cooperation," foreign ministry spokeswoman Hua Chunying said.

She spoke after US National Security Advisor Tom Donilon said in New York on Monday that Beijing must take steps to investigate and stop cybercrime.

Last month a report from US security firm Mandiant said a unit of China's People's Liberation Army had stolen hundreds of terabytes of data from at least 141 organizations, mostly based in the United States.

A US congressional report last year named China as "the most threatening actor in cyberspace."

Beijing has flatly rejected such accusations. Following the Mandiant report. China's defense ministry countered that US-based hackers carried out regular attacks last year on two Chinese military websites.