The emerging threat from the cyber world, particularly from China, has a "devastating potential" and there is need to address this, a top American military leader has said.

"It (cyber warfare) is an area that has received great focus on the part of the United States and other countries.

"It is an area of warfare, cyber warfare, that I think needs to be one on which we focus greatly and has devastating potential on the downside," Admiral Mike Mullen, Chairman of the Joint Chiefs of Staff, told reporters at a news conference here.

Mullen said a lot of of changes have been made inside the Department of Defence and the US government, and they are working towards a very robust system.

"But the threat's significant, and the threat from China is significant. There are other threats out there that we see routinely. And I think we've got to come to a place where those threats are diminished, if not eliminated," he said.

He, however, refrained from going into details of the cyber warfare.

"I would never go in, certainly in any area of warfare into details on threat except to say they're substantial. That said, I've been around long enough to know you just can't wish them away or ask them to go away,"

It is an area, as is space -- cyberspace and space. It is an area with no rules. There are no boundaries. It happens at the speed of light. There are non-state-sponsored entities, in addition to state-sponsored entities, that are involved in this, Mullen said.

"So it's an enormously complex and critical area that all of us need to understand a lot better and do a lot more about," the official said.