Barack Obama: US sees 'ramping up' of cyber threats

President Barack Obama says the US has seen a "steady ramping up" of cyber security attacks in an interview with US broadcaster ABC News.

Last month, a US cyber security firm said a secretive branch of China's military was probably one of the world's "most prolific cyber espionage groups", believed to have stolen hundreds of terabytes of data from at least 141 organisations around the world.

"We have seen a steady ramping up of cyber security threats," Mr Obama said in the interview. "Some are state sponsored, some are just sponsored by criminals."

The US president added that he had made clear to China and "some other state actors" that they expect them to abide by international rules.